Response of mucous-secreting cells of the gills and intestine to stress during induced spawning of gray mullet, Mugil cephalus

Introduction: An excess of mucus has been observed in the water during induction of mullet spawning. Few data are available on the physiology of mullets during the induced spawning, especially data on the response of mucous-secreting cells in the gills and intestine

Aim of the work: The aims of the present studies were to evaluate the effects of stress on the mucous-secreting cells in the gills and intestine during induced spawning of Mugil cephalus [Teleostei]

Materials and methods: Quantification of possible cell hyperplasia [or depletion] and the chemical composition of the mucous cells during induction of M. cephalus spawning was carried out using histochemical techniques

Results: The majority of mucous cells were concentrated at the edge of the gill filaments. The mucous cell density in the gills was significantly increased during spawning, but it was significantly decreased during preoviposition mortality. However, the mucous cell density in the mucosal layer of the intestine was significantly decreased during spawning and at preoviposition mortality. The size of mucous cells in both the gills and the intestine was significantly decreased during spawning and at preoviposition mortality, whereas its size was significantly increased in the gills after spawning. Two types of glycoproteins [GPs] [acid and neutral] were identified in the mucous cells of the gill and intestine epithelium of M. cephalus. During induction of spawning, the amount of GPs in the mucous cells altered. The amount of each variety of the carbohydrate [intensity of reaction] differed at the different stages during spawning. In general, the secretion of acidic mucous was increased during spawning

Conclusion: The decrease in the GP contents in mucous cells of M. cephalus, as a result of their hypersecretion in response to stress early during handling and acclimation, decreased the production of mucus and reduced its protective role against desiccation of gill and intestine tissue when the ion concentration changed in water during acclimation and induced spawning. This may be considered one of the possible reasons for mortality. Therefore, caution must be exercised not only in acclimation of fish but also in minimization of exposure of fish to stress during induction of spawning

Effect of stress during handling, seawater acclimation, confinement, and induced spawning on plasma ion levels and somatolactin immunoreactivity in mature female thin -lipped gray mullet, Liza ramada

Understanding the physiological picture of fish during the reproductive cycle, seawater acclimation, and induced spawning is of essential value to know the possible reasons of preoviposition mortality and to develop successful hatchery technology. Determination of the effect of different stress factors on hydro-mineral balance as well as changes in somatolactin [SL] immunoreactive cells in mature Liza ramada females. Water chemistry and the different plasma ion levels were measured. Immunocytochemical staining for the sections of the pituitary gland was performed to describe the activity of SL immunoreactive cells. The plasma levels of PO[3-4], Na[+], K[+], Ca[2+], and Mg[2+] showed a slight increase during transportation without anesthesia. The concentrations of these minerals returned to the initial levels by using clove oil [5 mg/I] as anesthetic. However, their levels decreased during seawater acclimation and gradually increased with confinement to reach the initial values. Furthermore, the levels of PO[3-4], Na[+], K[+], Ca[2+], and Mg[2+] were significantly [P

Estudio experimental de la depresión por estrés social / Experimental study of depression by social stress

Se estudió experimentalmente la depresión reactiva en monos inducida por conflitos sociales. Con este fin se usó como modelo la formación de nuevos grupos con animales desconocidos entre sí, ya que este procedimiento induce estrés asociado a un cuadro somático y conductual de depresión emocional. Se emplearon dos grupos de monos (Cercopithecus aethiops) que se formaron simultáneamente en jaulas gemelas y contiguas, con igual composición social (cuatro hembras y un macho adulto y cuatro juveniles de ambos sexos en cada grupo). La conducta social se registró diariamente durante una hora en cada grupo y se analizaron las conductas afiliativas de juntarse, espulgarse, el juego y la conducta sexual. Las conductas de rechazo estudiadas fueron los desplazamientos, las fintas, y los ataques. Durante las primeras cinco semanas después de la formación murieron dos hembras adultas y dos juveniles en cada grupo. Dos de los juveniles murieron el día de la formación a consecuencia de las heridas recibidas y los dos restantes murieron de neumonía unos días después. En cambio las necropsias de las hembras adultas mostraron hemorragias petequiales e hipertrofia de las glándulas suprarrenales y en un caso úlceras gástricas. Los animales sobrevivientes se continuaron estudiando durante dos meses más con el propósito de permitir la consolidación de lazos afiliativos y posteriormente ambos grupos se unieron en uno solo. La conducta social de las hembras deprimidas que murieron se comparó con la de las hembras que lograron adaptarse socialmente y por tanto sobrevivir. Las diferencias más significativas ocurrieron en la conducta afiliativa más frecuente (juntarse con otro u otros) así como en la conducta de rechazo más frecuente (los desplazamientos). El grupo de hembras que murieron se juntó primordialmente con los juveniles mostrando frecuenta progresivamente decrecientes...

Studies in tissue glycogen in acute stress.

The glycogen was estimated in liver, cardiac and skeletal muscles during the recovery period after electro-shock. The supercompensation in the level of glycogen was observed in cardiac and skeletal muscles at 1 1/2 and 5 hrs respectively during the recovery period, after electro-shock. The liver glycogen level was lower than the control value after electro-shock at least upto 5 hrs of recovery period. Further, the glycogen level was observed to be minimum when the ventricular glycogen showed its supercompensation at 1 1/2 hr of recovery period. The glycogen level of those three tissues returned to control level after 24 hrs of electro-shock.

Effect of foot-electroshock stress on cholinergic activity, tissue glycogen and blood sugar in albino rats.

The immediate or 24 hr delayed effects of 1-day (1-DS) or (7-DS) foot-electroshock stress in albino rats were studied on cardiac acetylcholine (ACh), blood and cardiac cholinesterase (ChE) activities, cardiac, hepatic and muscle glycogen contents and blood sugar concentrations. The effects of physostigmine (PHY), atropine, 6-hydroxydopamine (6-HD), vagotomy and adrenalectomy on 1-DS induced changes were also studied. 1-DS produced an increase in cardiac ACh content which lasted for 24 hr but repeated stress showed phenomenon of adaptation. There seems to be activation of autonomic cholinergic system in stress. 1-DS and 7-DS produced a short-lived inhibition of blood ChE activity and 7-DS also of cardiac ChE activity. Inhibition of ChE activity was probably related to release of adrenaline from adrenal medulla. 1-DS produced hepatic and muscle glycogenolysis with slight hypoglycaemia but without any effect on cardiac glycogen. Following repeated stress there was a phenomenon of adaptation. The hepatic and muscle glycogenolysis produced by stress is due to the release of adrenaline from adrenal medulla. Normally functioning cardiac cholinergic system seems to have a protective effect on heart against stress, in the absence of which cardiac glycogenolysis is induced by stress.