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1.
Int. j. morphol ; 36(3): 895-900, Sept. 2018. tab, graf
Article in Spanish | LILACS | ID: biblio-954204

ABSTRACT

La reserpina es un antipsicótico e hipotensor arterial que reduce significativamente los niveles de monoaminas centrales, y también es utilizada para modelar los cuadros depresivos humanos en animales de laboratorio. Este trabajo estudió, en ratas Wistar machos adolescentes, cómo la reserpina afecta indicadores moleculares de la función testicular, la cual se ha visto alterada en humanos deprimidos. Una semana luego de finalizado el tratamiento con reserpina (4 dosis de 0,0 o 1,0 mg/Kg, cada 2 días) la respuesta ansiosa y depresiva fue evaluada en un laberinto en cruz elevado. Posteriormente, se sacrificaron los animales y disecaron los testículos, los cuales fueron fijados e incluidos en bloques de parafina de donde se obtuvieron cortes histológicos de 6 µm de espesor. Estos se utilizaron para medir el diámetro de los túbulos seminíferos y para medir por inmunohistoquímica el porcentaje de células intersticiales (células de Leydig) positivas a (1) Factor neurotrófico derivado del cerebro, (2) antígeno nuclear de células en proliferación (BDNF y PCNA, respectivamente, por sus siglas en inglés), y a (3) caspasa-3. Se obtuvo también un índice de positividad al receptor de andrógenos en las células intersticiales. La expresión del receptor de andrógeno fue evaluada utilizando una escala semicuantitativa de escores (0, 1, 2 y 3) y el resto de las moléculas por presencia o ausencia de expresión de cada antígeno investigado en 300 células por preparado. Los resultados comportamentales indicaron alteraciones en la respuesta de ansiedad y una significativa depresión motora (e.g., mayor latencia en conductas de escape del sector blanco) en los animales tratados con reserpina. No se observaron diferencias en los diámetros de los túbulos seminíferos ni en la expresión del receptor de andrógeno, mientras que sí se encontró mayor proporción de células intersticiales positivas a BDNF y PCNA, y menor proporción de células positivas a caspasa-3, en los animales tratados. Los resultados corroboran la capacidad de la reserpina para reproducir rasgos comportamentales de la depresión. La administración de la droga, sin embargo, no parece reproducir a nivel testicular los efectos deletéreos encontrados en humanos deprimidos, e incluso los resultados sugieren que la reserpina puede mejorar algunos aspectos de la funcionalidad testicular relacionadas con la actividad de las células intersticiales en ratas.


Reserpine, a drug that depletes central monoamines, has been used as an antipsychotic and arterial hypotensive, and to model depression in animals. The present study analyzed, in adolescent male rats, the effects of chronic reserpine treatment on molecular indexes of testicular function. A week after termination of the treatment (4 doses of 0,0 or 1,0 mg/Kg/every 48 h) the animals were tested for anxiety response and depression patterns in an elevated plus maze. They were then euthanized, their testes dissected, fixed and embedded in paraffin to obtain blocks. Histological sections (6 µm) were obtained and used to measure the diameter of seminiferous tubules and the expression in Leydig cells of Brain-derived neurotrophic factor (BDNF), Proliferating cell nuclear antigen (PCNA), Caspase-3 and androgen receptors, by immunohistochemistry. Behavioral results indicated significant alterations in anxiety responses and a significant motor depression (e.g., greater latency to escape from the white sector). There were no differences between groups in the diameter of seminiferous tubules nor in the androgen receptors positivity. Reserpine-treated animals, however, exhibited more BDNF and PCNA positive cells, and less positive Caspase-3 cells in Leydig cells, than control animals. The results corroborate the efficacy of reserpine to reproduce some of the behavioral components of depression. The drug, however, does not seem to exert in rats the same effects on testicular function that have been found in humans diagnosed with depression. Furthermore the drug seems to enhance some aspects of testicular function related to Leydig cells function in rats.


Subject(s)
Animals , Male , Rats , Reserpine/pharmacology , Testis/drug effects , Antipsychotic Agents/pharmacology , Proliferating Cell Nuclear Antigen/drug effects , Brain-Derived Neurotrophic Factor/drug effects , Leydig Cells/drug effects , Testis/cytology , Immunohistochemistry , Rats, Wistar , Caspase 3/drug effects
2.
Braz. j. med. biol. res ; 41(10): 920-925, Oct. 2008. ilus, graf
Article in English | LILACS | ID: lil-496807

ABSTRACT

Dopaminergic neurotransmission is involved in the regulation of sleep. In particular, the nigrostriatal pathway is an important center of sleep regulation. We hypothesized that dopaminergic neurons located in substantia nigra pars compacta (SNpc) could be activated by gentle handling, a method to obtain sleep deprivation (SD). Adult male C57/BL6J mice (N = 5/group) were distributed into non-SD (NSD) or SD groups. SD animals were subjected to SD once for 1 or 3 h by gentle handling. Two experiments were performed. The first determined the activation of SNpc neurons after SD, and the second examined the same parameters after pharmacologically induced dopaminergic depletion using intraperitoneal reserpine (2 mg/kg). After 1 or 3 h, SD and NSD mice were subjected to motor evaluation using the open field test. Immediately after the behavioral test, the mice were perfused intracardially to fix the brain and for immunohistochemical analysis of c-Fos protein expression within the SNpc. The open field test indicated that SD for 1 or 3 h did not modify motor behavior. However, c-Fos protein expression was increased after 1 h of SD compared with the NSD and 3-h SD groups. These immunohistochemistry data indicate that these periods of SD are not able to produce dopaminergic supersensitivity. Nevertheless, the increased expression of c-Fos within the SNpc suggests that dopaminergic nigral activation was triggered by SD earlier than motor responsiveness. Dopamine-depleted mice (experiment 2) exhibited a similar increase of c-Fos expression compared to control animals indicating that dopamine neurons are still activated in the 1-h SD group despite the exhaustion of dopamine. This finding suggests that this range (2-5-fold) of neuronal activation may serve as a marker of SD.


Subject(s)
Animals , Male , Mice , Dopamine/metabolism , Proto-Oncogene Proteins c-fos/metabolism , Sleep Deprivation/metabolism , Substantia Nigra/metabolism , Immunohistochemistry , Motor Activity/physiology , Reserpine/pharmacology , Time Factors
3.
Indian J Exp Biol ; 2006 Nov; 44(11): 913-7
Article in English | IMSEAR | ID: sea-61816

ABSTRACT

Green tea (C. sinensis) extract (GTE) dose dependently produced reversal of despair in normal, reserpinised and diabetic mice, thereby demonstrating an antidepressant effect. Although the exact mechanism is yet to be explored, the possible inhibition of catechol-o-methyl transferase and monoamine oxidase enzymes may be responsible for antidepressant activity of GTE.


Subject(s)
Animals , Antidepressive Agents/pharmacology , Behavior, Animal/drug effects , Camellia sinensis/chemistry , Diabetes Mellitus, Experimental/blood , Habituation, Psychophysiologic/drug effects , Helplessness, Learned , Male , Mice , Mice, Inbred Strains , Phytotherapy/methods , Plant Extracts/pharmacology , Reserpine/pharmacology , Streptozocin , Swimming
4.
Indian J Physiol Pharmacol ; 2006 Oct-Dec; 50(4): 409-15
Article in English | IMSEAR | ID: sea-106608

ABSTRACT

The objective of the present study was to evaluate the antidepressant action of Withania somnifera (WS) as well as its interaction with the conventional antidepressant drugs and to delineate the possible mechanism of its antidepressant action using forced swimming model in mice. Effect of different doses of WS, fluoxetine and imipramine were studied on forced swimming test induced mean immobility time (MIT). Moreover effect of WS 100 mg/kg, i.p. was observed at different time intervals. Effect produced by combination of sub therapeutic doses of WS with imipramine (2.5 mg/kg, i.p.) as well as fluoxetine (2.5 mg/kg, i.p.) were also observed. Effect of WS (100 mg/kg, i.p.) as well as combination of WS (37.5 mg/kg, i.p.) with either imipramine (2.5 mg/kg, i.p.) or fluoxetine (2.5 mg/kg, i.p.) were observed in mice pretreated with reserpine (2 mg/kg, i.p.) and clonidine (0.15 mg/kg, i.p.). Effects of prazosin (3 mg/kg, i.p.) or haloperidol (0.1 mg/kg, i.p.) pre-treatment were also observed on WS induced decrease in MIT. WS produced dose dependent decrease in MIT. Maximum effect in MIT was observed after 30 min of treatment with WS 100 mg/kg, i.p. Combination of WS (37.5 mg/kg, i.p.) with imipramine (2.5 mg/kg, i.p.) or fluoxetine (2.5 mg/kg, i.p.) also produced significant decrease in the MIT. Clonidine and reserpine induced increase in MIT, was significantly reversed by treatment with WS (100 mg/kg, i.p.) as well as combination of WS (37.5 mg/kg, i.p.) with either imipramine (2.5 mg/kg, i.p.) or fluoxetine (2.5 mg/kg, i.p.). Pre-treatment with prazosin but not haloperidol, significantly antagonized the WS (100 mg/kg, i.p.) induced decrease in MIT. It is concluded that, WS produced significant decrease in MIT in mice which could be mediated partly through a adrenoceptor as well as alteration in the level of central biogenic amines.


Subject(s)
Adrenergic alpha-Agonists/pharmacology , Adrenergic alpha-Antagonists/pharmacology , Animals , Antidepressive Agents , Antidepressive Agents, Second-Generation/pharmacology , Antidepressive Agents, Tricyclic/pharmacology , Antipsychotic Agents/pharmacology , Clonidine/pharmacology , Drug Interactions , Female , Fluoxetine/pharmacology , Imipramine/pharmacology , Male , Mice , Motor Activity/drug effects , Plant Extracts/pharmacology , Prazosin/pharmacology , Reserpine/pharmacology , Swimming/physiology , Withania/chemistry
5.
Indian J Exp Biol ; 2004 Apr; 42(4): 368-72
Article in English | IMSEAR | ID: sea-60273

ABSTRACT

Insulin produces seizures in healthy and diabetic animals. Amongst suggested mechanisms, the role of neuromodulators and neurotransmitters is not clear. The present study explores the mechanisms involved in insulin-induced convulsions. Convulsions were induced in Swiss male albino mice with graded doses of insulin. Blood sugar levels were measured prior to and after the first convulsion. Drugs like 5-HTP (5-HT precursor), pCPA (5-HT depletor), ondansetron (5-HT3 antagonist), ketanserin (5-HT, antagonist), ketamine (NMDA antagonist), 1-dopa (dopamine precursor) and reserpine (amine depletor) were studied for interaction with convulsive behaviour induced by insulin. Insulin in 2 IU/kg dose did not produce convulsions while 4 and 8 IU/kg doses produced convulsions in 50% and 100% of animals respectively. 5-HTP, ondansetron, ketanserin, ketamine and l-dopa significantly protected/inhibited animals from convulsions at all studied doses of insulin. On the contrary, pCPA and reserpine potentiated insulin induced convulsions. Insulin caused mortality in 40 and 100% animals with 4 and 8 IU/kg doses respectively. pCPA and reserpine treatments caused mortality at all doses of insulin, while other drugs did not influence insulin induced mortality. Blood sugar levels were reduced in all groups irrespective of the presence or absence of convulsions. A definitive link of serotonergic, dopaminergic and excitatory amino acid pathways in mediating insulin-induced hypoglycemic convulsions is suggested.


Subject(s)
5-Hydroxytryptophan/pharmacology , Animals , Anticonvulsants/pharmacology , Antihypertensive Agents/pharmacology , Blood Glucose/analysis , Dopamine/metabolism , Dopamine Agents/pharmacology , Drug Interactions , Excitatory Amino Acid Antagonists/pharmacology , Excitatory Amino Acids/metabolism , Hypoglycemia/chemically induced , Hypoglycemic Agents/toxicity , Insulin/toxicity , Ketamine/pharmacology , Ketanserin/pharmacology , Levodopa/pharmacology , Male , Mice , Reserpine/pharmacology , Seizures/chemically induced , Serotonin/metabolism , Serotonin Antagonists/pharmacology , Survival Rate
6.
Indian J Exp Biol ; 2002 Nov; 40(11): 1269-74
Article in English | IMSEAR | ID: sea-62773

ABSTRACT

Self-mutilation or self-injurious behaviour is a well known behavioural disorder in humans. The proposition that this behaviour in animals is a response to chronic pain of peripheral nerve injury has been met with controversy. In the present study a pharmacological model, which produces no sensory or motor loss was used to study how autotomy is related to pain. In a group of rats autotomy was induced by amphetamine in phenoxybenzamine and reserpine treated animals. The pain tests, both phasic and tonic were then performed. The results of this study showed that a total analgesia was produced in both phasic and tonic pain tests, in animals that exhibited autotomy. Injection of naloxone in these animals prevented autotomy. A correlation between autotomy and no pain is suggested in this pharmacological model of autotomy.


Subject(s)
Adrenergic Uptake Inhibitors/pharmacology , Adrenergic alpha-Antagonists/pharmacology , Amphetamine/pharmacology , Analgesia , Animals , Behavior, Animal , Central Nervous System Stimulants/pharmacology , Chronic Disease , Denervation , Disease Models, Animal , Male , Naloxone/therapeutic use , Narcotic Antagonists/therapeutic use , Pain/physiopathology , Pain Measurement , Phenoxybenzamine/pharmacology , Rats , Rats, Wistar , Reserpine/pharmacology , Self Mutilation/chemically induced
7.
An. acad. bras. ciênc ; 71(2): 189-201, jun. 1999. ilus, graf
Article in English | LILACS | ID: lil-234513

ABSTRACT

Although recently developed drugs have brought significant improvement, the treatment of psychotic disorders still presents serious drawbacks. Since inherent complexity and lack of satisfactory understanding of the underlying pathophysiology impose limits for rational drug design, resourceful approaches in the search for antipsychotics are pertinent. This paper reports pharmacological properties of alstonine, a heteroyohimbine type alkaloid, Which exbitited an antipsychotic-like profile, inhibiting amphetamine-induced lethaly, apomorphine-induced steotypy and potentiating barbiturate-induced slleping time. Atypical features of alstonine were the prevention of haloperidol-induced catalepsy and lack of direct interaction with D1, D2 and 5-HT2A receptors, classically linked to antipsychotic mechanism of action.


Subject(s)
Animals , Male , Mice , Antipsychotic Agents/pharmacology , Plants, Medicinal , Secologanin Tryptamine Alkaloids/pharmacology , Amphetamine/antagonists & inhibitors , Apomorphine/antagonists & inhibitors , Barbiturates/antagonists & inhibitors , Central Nervous System Stimulants/antagonists & inhibitors , Chlorpromazine/pharmacology , Clozapine/pharmacology , Diazepam/pharmacology , Emetics/antagonists & inhibitors , Haloperidol/pharmacology , Hypnotics and Sedatives/antagonists & inhibitors , Nigeria , Pentobarbital/pharmacology , Reserpine/pharmacology , Sleep/drug effects , Stereotyping , Sulpiride/pharmacology
8.
Indian J Exp Biol ; 1999 May; 37(5): 455-60
Article in English | IMSEAR | ID: sea-62326

ABSTRACT

The effect of Indian red scorpion (Mesobuthus tamulus concanesis, Pocock; MBT) venom was investigated on isolated rat right atrial preparations. MBT venom (0.001-3.0 micrograms/ml) exhibited a peculiar concentration-response pattern with respect to rate. The venom concentrations between 0.001-0.01 microgram/ml increased the atrial rate (phase I), followed by a relative decrease with 0.03-0.3 microgram/ml (phase II), and then an abrupt increase with 0.6-3.0 micrograms/ml (phase III). On the other hand, the force was unaltered by venom at phases I and II, while an increase was seen at phase III (3.0 micrograms/ml). Propranolol (0.1 microM) completely blocked the cardiostimulant action of venom at phase III. Further, this stimulant action of venom was absent in atria obtained from reserpinized animals. Pretreatment with atropine (0.3 microM), produced tachycardia at concentrations 0.1-0.3 microgram/ml of venom. But, hexamethonium (30 microM) had no influence on the venom (0.1 microgram/ml)-induced alterations in rate. However, MBT venom increased the acetylcholinesterase (AChE) activity (2-3 fold) in a concentration-dependent manner. Tetrodotoxin (2 microM), did not block the increase in rate produced by 0.01 microgram/ml of venom. Results suggest that, MBT venom-induced alterations of cardiac rhythmicity are mediated through cholinergic as well as adrenergic mechanisms depending upon the concentrations. The modulation of atrial rate at very low concentrations may be due to the direct action of venom on the atrium.


Subject(s)
Acetylcholinesterase/metabolism , Animals , Atropine/pharmacology , Dose-Response Relationship, Drug , Heart/drug effects , Heart Atria/drug effects , Hexamethonium/pharmacology , Male , Muscarinic Antagonists/pharmacology , Myocardial Contraction/drug effects , Rats , Reserpine/pharmacology , Scorpion Venoms/administration & dosage , Tetrodotoxin/pharmacology
9.
Indian J Exp Biol ; 1999 Mar; 37(3): 234-7
Article in English | IMSEAR | ID: sea-60788

ABSTRACT

Roxindole, a DA D2 receptor agonist (2-16 mg/kg) produced dose-dependent increase in percentage antinociception. The effect which was blocked by DA D2 antagonist (-)sulpiride (50 mg/kg) and 5-HT1A receptor antagonist (-) pindolol (5 mg/kg). Roxindole (4 and 8 mg/kg) reversed both naloxone (20 mg/kg)-induced hyperalgesia and reserpine (2 mg/kg)-induced hyperalgesia. This reversal was sensitive to blockade by both (-)sulpiride (50 mg/kg) and (-) pindolol (5 mg/kg). The present study suggests that roxindole-induced antinociception is mediated by postsynaptic DA D2 and 5-HT1A receptors.


Subject(s)
Analgesics/pharmacology , Animals , Dopamine Agonists/pharmacology , Indoles/pharmacology , Mice , Mice, Inbred BALB C , Naloxone/pharmacology , Nociceptors/drug effects , Pindolol/pharmacology , Pyridines/pharmacology , Receptors, Dopamine D2/physiology , Receptors, Serotonin/physiology , Receptors, Serotonin, 5-HT1 , Reserpine/pharmacology , Sulpiride/pharmacology
10.
Acta physiol. pharmacol. ther. latinoam ; 49(4): 210-4, 1999. tab, graf
Article in English | LILACS | ID: lil-260727

ABSTRACT

The contractile effect of serotonin was studied in rat vas deferens, in comparison with that of noradrenaline and tyramine, after reserpine treatment, surgical denervation, and transplantation to the colon. In reserpinized animals the effect of 5HT resembled that of tyramine, since it was strikingly reduced, in spite of a small residual effect, showing that in normal preparations the effects of 5HT and tyramine are predominantly duc to the release of endogenous noradrenaline. However, in denervated or transplanted vas deferens, in which the effect of tyramine is also abolished, the effect of 5HT was potentiated. It is suggested that after chronic, long lasting depletion of endogenous noradrenaline, there are alternate mechanisms that are generated to improve the contractile effect of 5HT, but not of tyramine. The nature of these mechanisms is still unknown.


Subject(s)
Animals , Male , Rats , Muscle Contraction/drug effects , Serotonin/pharmacology , Vas Deferens/physiology , Adrenergic Uptake Inhibitors/pharmacology , Denervation , Dose-Response Relationship, Drug , Norepinephrine/pharmacology , Rats, Wistar , Reserpine/pharmacology , Sympathomimetics/pharmacology , Tyramine/pharmacology , Vas Deferens/innervation , Vas Deferens/transplantation
11.
Article in English | LILACS | ID: lil-168105

ABSTRACT

The effects of estrogen (E), progesterone (P) and estrogen plus progesterone (E+P) treatment on Cainduced contraction in the KCL-depolarized uterine muscle, and the influences on the Ca2+ antagonism induced by reserpine and verapamil "in vivo" were studied. Uterine muscles from rats in estrus were taken as controls. Uteri from spayed untreated rats showed the same sensivity to Ca2+ as those from estrus rats, but castration decreased maximal contractile tension to Ca2+ and Ca2+ thereshold. P tratment failed to modified the effects of castration on the responses to Ca2+. E or E+P treatments decreased the sensitivity to Ca2+ but only E+P increased slope values and maximal contractile tension. E and E+P increased the potency of verapamil Ca2+ antagonism but none the treatments modified reserpine direct inhibitory effects. The results obtained suggest that alterations on uterine contractility by hormone treatment are the result of complex interactions between both genomic effects on the contractile process as well as nongenomic direct actions of the hormones on Ca2+ membrane permeability.


Subject(s)
Animals , Female , Rats , Calcium/pharmacology , Uterine Contraction , Estradiol/pharmacology , Myometrium/drug effects , Progesterone/pharmacology , Calcium Channel Blockers/pharmacology , Calcium/antagonists & inhibitors , Castration , Potassium Chloride/pharmacology , Dose-Response Relationship, Drug , Drug Therapy, Combination , Estradiol/therapeutic use , Neuromuscular Depolarizing Agents , Progesterone/therapeutic use , Regression Analysis , Reserpine/pharmacology , Verapamil/pharmacology
12.
Indian J Exp Biol ; 1994 Mar; 32(3): 172-5
Article in English | IMSEAR | ID: sea-60377

ABSTRACT

Possible involvement of dopaminergic (DAergic) system in forced swimming-induced immobility (despair behaviour) was investigated in mice. B-HT 920 (0.05 and 0.1 mg/kg), a post-synaptic DAergic agonist, produced a dose dependent reduction in immobility period, which was sensitive to blockade by haloperidol (0.5 mg/kg) and sulpiride (100 mg/kg). This effect was also blocked by alpha 2 antagonist yohimbine (5 mg/kg). SKF 38393 (5 mg/kg), a D1-DA agonist potentiated the action of B-HT 920. Reserpinization (2 mg/kg, 24 hr prior) produced despair immobility in mice. When a low dose of B-HT 920 (0.05 mg/kg) was given to reserpinized animals, the duration of immobility period was further increased. But on the other hand, a higher dose (0.1 mg/kg) of it reduced reserpine-induced immobility. Desipramine (5 and 10 mg/kg), elicited a dose dependent reduction in the immobility period, which was sensitive to blockade by sulpiride (100 mg/kg). Desipramine (10 mg/kg) showed a diphasic response in combination with B-HT 920, i.e., a potentiation of the response due to a low dose of B-HT 920 (0.05 mg/kg) and an antagonism of the response due to a higher dose of B-HT 920 (0.1 mg/kg), respectively. SKF 38393 (5 mg/kg), potentiated the action of desipramine (5 mg/kg). SKF 38393 (5 mg/kg) further potentiated the action of desipramine (5 mg/kg) and B-HT 920 (0.05 mg/kg). These observations suggests that B-HT 920 reduces behavioural immobility by DAergic mechanism and desipramine also modulates D2-DA receptors in its anti-depressant action.


Subject(s)
2,3,4,5-Tetrahydro-7,8-dihydroxy-1-phenyl-1H-3-benzazepine/pharmacology , Animals , Antidepressive Agents/pharmacology , Azepines/pharmacology , Desipramine/pharmacology , Drug Interactions , Escape Reaction/drug effects , Female , Haloperidol/pharmacology , Male , Mice , Motor Activity/drug effects , Receptors, Dopamine/classification , Reserpine/pharmacology , Sulpiride/pharmacology , Swimming , Yohimbine/pharmacology
13.
Indian J Exp Biol ; 1994 Mar; 32(3): 176-9
Article in English | IMSEAR | ID: sea-61727

ABSTRACT

Presence of specific dopamine (DA) receptors and their characterization was attempted in rat anococcygeus muscle preparation. Dopamine (10(-6) M) and B-HT 920 (10(-6) M) produced concentration dependent contractions of the rat anococcygeus muscle preparation. The response of DA was shifted towards right in presence of haloperidol (10(-6) M; pA2 = 6.8) and sulpiride (10(-4) M) in a competitive manner. Alpha 2 antagonists yohimbine (10(-5) M) and idazoxan (10(-5) M) blocked the response to DA in a competitive manner, while alpha 1 antagonist prazosin (10(-5) M) completely blocked the response to DA. SCH 23390 (10(-5) M), a D1 DA antagonist potentiated the response to DA. Reserpinization (5 mg/kg, 24 hr prior) brought about a shift towards the right, and this response was similarly blocked by haloperidol, sulpiride and yohimbine without affecting the maximum response. Desipramine (10(-5) M) blocked the response of DA in a non-competitive manner. Pretreatment of animals with desipramine (10 mg/kg) followed by reserpine, brought about a reversal of action of reserpine. The response to B-HT 920 (10(-6) M), was blocked similarly by haloperidol and yohimbine. However, the effect of desipramine was more pronounced when compared to DA per se. SKF 38393, a D1 DA agonist, potentiated the response to B-HT 920. The findings suggest the presence of both D1 and D2 DA receptors in rat anococcygeus muscle and that DA also acts on adrenergic receptors to produce a contractile response of this muscle preparation.


Subject(s)
2,3,4,5-Tetrahydro-7,8-dihydroxy-1-phenyl-1H-3-benzazepine/pharmacology , Animals , Azepines/pharmacology , Benzazepines/pharmacology , Desipramine/pharmacology , Dioxanes/pharmacology , Dopamine/pharmacology , Female , Haloperidol/pharmacology , Idazoxan , Male , Muscle Contraction/drug effects , Prazosin/pharmacology , Rats , Receptors, Adrenergic/drug effects , Receptors, Dopamine/classification , Reserpine/pharmacology , Sulpiride/pharmacology , Yohimbine/pharmacology
14.
Arch. Inst. Nac. Neurol. Neurocir ; 8(3): 123-8, sept.-oct. 1993. ilus, tab
Article in English | LILACS | ID: lil-196029

ABSTRACT

Se ha propuesto que en el tegmento pontomesencefálico, específicamente en la región denominada "área X" (AX) y en el núcleo parabraquial lateral (Pbl), se localizan las células generadoras de la actividad ponto-geniculo-occipital (PGO) que ocurre durante el sueño paradójico. Las evidencias se basan en el análisis de la actividad PGO registrada a nivel tálamico (en el núcleo geniculado lateral; NGL). Sin embargo, la actividad PGO también puede ser registrada en el núcleo abducens (VI par). Con el fin de determinar si la región pontomesencefálica también participa en la regulación de la actividad PGO que se registra a nivel pontino, realizamos pequeñas lesiones electroliticas en el Pbl en el AX, registrado simultáneamente la actividad PGO en el NGL y en el VI par. Se utilizaron gatos anestesiados, curarizados y pretratados con reserpina. La lesión del AX suprimió la actividad PGO registrada en el NGL pero no afectó las espigas registradas a nivel pontino. La lesión del Pbl no modificó la actividad PGO registrada en el NGL ni en el VI par. Estos datos no apoyan la influencia del AX del Pbl sobre la actividad PGO registrada a nivel pontino y sugieren que la región pontomesencefálica sólo juega un papel en la transmisión de las espigas PGO desde el puente al NGL.


Subject(s)
Animals , Cats , Abducens Nerve/physiology , Cranial Nerves/physiopathology , Reserpine/pharmacology , Urethane/administration & dosage
15.
Indian J Physiol Pharmacol ; 1993 Apr; 37(2): 109-14
Article in English | IMSEAR | ID: sea-106752

ABSTRACT

Reserpine induced supersensitivity to norepinephrine (NE) in rat vas deferens was sought by alteration of Mg++ and Ca++ concentration in incubation medium in the absence and presence of EDTA. Vas deferens incubated in Mg++ free and Mg++ excess media showed supersensitivity and subsensivity to NE respectively. Alterations in the sensitivity to NE produced by varying the concentrations of Mg++ were comparatively less. In the presence of EDTA, vas deferens obtained from reserpinized animals showed subsensitivity in normal and Mg++ excess media and supersensitivity in Mg++ free medium. In the presence of EDTA, reserpinized preparations showed slight supersensitivity in normal Mg++ medium, marked supersensitivity in Mg++ free and lesser subsensitivity in Mg++ excess medium. Probably EDTA by more effectively removing Mg++ from the membrane binding sites by chelation makes the membrane permeable to Ca++ leading to supersensitivity to NE (observed only in the presence of EDTA). These results suggest that the failure of reserpine to induce supersensitivity to NE in rat vas deferens may be due to an enhanced antagonism of Mg++ on Ca++ movements in this preparations due to the poor capacity of rat tissue to retain Ca++.


Subject(s)
Animals , Calcium/metabolism , Edetic Acid , Magnesium/pharmacology , Male , Muscle Contraction/drug effects , Muscle, Smooth/drug effects , Norepinephrine/antagonists & inhibitors , Rats , Rats, Wistar , Reserpine/pharmacology , Vas Deferens/drug effects
16.
Indian J Exp Biol ; 1993 Apr; 31(4): 360-4
Article in English | IMSEAR | ID: sea-58127

ABSTRACT

IDPH-791, when injected (ip) to mice potentiated the pentobarbitone sleeping time in a dose dependent manner. Involvement of neurotransmitters and receptors in this effect was studied using various receptor blockers, enzyme inhibitors, agonist and an amine depletor. Pretreatment with high dose of yohimbine (0.5 mg/kg), haloperidol, cyproheptadine, atropine and a combination of atropine and yohimbine significantly reversed the activity. Physostigmine, diethyldithiocarbamate and high dose of apomorphine (2.5 mg/kg) potentiated the subminimal effect of IDPH-791, whereas low dose of apomorphine (0.1 mg/kg) failed to potentiate. However, reserpine significantly reversed this response. Prazosin, phenoxybenzamine, low dose of yohimbine (0.25 mg/kg), propranolol, methysergide, mepyramine and cimetidine did not produce any change, thus ruling out the involvement of adrenergic, serotonergic and histaminergic systems. There seems to be simultaneous involvement of muscarinic receptors and postsynaptic dopamine (D2) receptors in IDPH-791 induced potentiation of pentobarbitone hypnosis.


Subject(s)
Animals , Cholinesterase Inhibitors/pharmacology , Dose-Response Relationship, Drug , Male , Mice , Muscle Relaxants, Central/pharmacology , Pentobarbital , Receptors, Neurotransmitter/antagonists & inhibitors , Reserpine/pharmacology , Sleep/drug effects , Thiazines/pharmacology , Triazoles/pharmacology
18.
Indian J Physiol Pharmacol ; 1991 Jul; 35(3): 165-9
Article in English | IMSEAR | ID: sea-108233

ABSTRACT

Self-aggression is a behavioural disorder in which an individual damages its own body parts by intense biting or scratching. Self aggression has been reported in human patients in Lesch-Nyhan syndrome and in cases of schizophrenia, depression, and congenital analgesia. In human patients as well as in experimental animals some kind of dysesthesia of the part of the body that is mutilated has been suggested. This study was conducted to find out the underlying pain mechanisms in self-aggressive behaviour arising out of stereotypy. The study was performed in 40 adult male rats. In all these animals, self-aggression was produced as part of amphetamine induced stereotyped behaviour. A predetermined scale was used for quantifying this behaviour. Reserpine and phenoxybenzamine pretreatment led to an increase in the incidence of self-aggression. Naloxone administration in reserpine pretreated animals led to a further significant increase in the incidence of self biting as compared to controls. From these studies it appears that self-aggressive behaviour may be associated with increased pain sensation.


Subject(s)
Aggression/drug effects , Amphetamine/pharmacology , Animals , Behavior, Animal/drug effects , Male , Naloxone/pharmacology , Norepinephrine/physiology , Pain/physiopathology , Phenoxybenzamine/pharmacology , Rats , Receptors, Opioid/drug effects , Reserpine/pharmacology , Self Mutilation/physiopathology , Time Factors
20.
Salud ment ; 12(3): 21-5, sept. 1989. tab, ilus
Article in Spanish | LILACS | ID: lil-89526

ABSTRACT

Se analizan los efectos de la administración de melatonina a dosis farmacológicas, sobre la actividad pontogenículo-occipital (PGO) del gato reserpinizado. Los experimentos se realizaron en gatos en preparación aguda, anestesiados con uretano y con respiración artificial, pretratados con reserpina (1mg/Kg ip) 17 horas antes del experimento. Después de un periodo de control, se administró melatonina a dosis de 0.5, 1, 10 y 50 mg/50 mg,Kg (iv) o vehículo. Se cuantificó la frecuencia por minuto de espigas PGO y se comprobaron ambas situaciones (control vs melatonina). Observamos una disminución de la frecuencia de espigas PGO conforme se incrementaba la dosis de melatonina, mientras que el vehículo no provocó modificaciones. Estos resultados sugieren que la melatonina juega un papel inhibidor sobre la actividad PGO, el cual puede interpretarse en diferentes niveles. Se discuten las interacciones con serotonina, con un posible receptor a melatonina localizado en la membrana celular de células de hipotálamo y a nivel subcelular o por posibles cambios en los diferentes pozos metabólicos de calcio, lo cual trae como resultado una serie de cambios en la bioquímica a nivel sináptico


Subject(s)
Cats , Animals , Male , Melatonin/administration & dosage , Brain Stem/physiology , Melatonin/pharmacology , Reserpine/pharmacology
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