Subject(s)
Heart Rate/physiology , Heart/growth & development , Animals , Electrocardiography , Heart/physiology , Periodicity , Rats , Rats, WistarSubject(s)
Duodenum/physiology , Muscle, Skeletal/physiology , Muscle, Smooth/physiology , Stomach/physiology , Animals , Animals, Newborn , Duodenum/growth & development , Muscle, Skeletal/growth & development , Muscle, Smooth/growth & development , Periodicity , Rats , Stomach/growth & development , VagotomySubject(s)
Muscle, Skeletal/innervation , Muscle, Skeletal/physiology , Muscle, Smooth/physiology , Stomach/physiology , Animals , Animals, Newborn , Electric Stimulation , Electrophysiology , Hindlimb , Muscle Contraction , Muscle Denervation , Muscle Development , Muscle, Skeletal/growth & development , Muscle, Smooth/growth & development , Pain/physiopathology , Periodicity , Rats , Rats, Wistar , Sciatic Nerve/growth & development , Sciatic Nerve/physiology , Stomach/growth & development , Stomach/innervationSubject(s)
Muscle Contraction/physiology , Muscle, Skeletal/physiology , Muscle, Smooth/physiology , Myocardial Contraction/physiology , Periodicity , Animals , Animals, Newborn , Electrophysiology , Heart/growth & development , Heart/physiology , Muscle Development , Muscle, Skeletal/growth & development , Muscle, Smooth/growth & development , Rats , Rats, WistarSubject(s)
Acetylcholine/pharmacology , Cardiac Output/physiology , Epinephrine/pharmacology , Heart/growth & development , Norepinephrine/pharmacology , Acetylcholine/physiology , Animals , Cardiac Output/drug effects , Drug Interactions , Epinephrine/physiology , Heart/drug effects , Heart/physiology , Heart Rate/drug effects , Heart Rate/physiology , Motor Activity/drug effects , Motor Activity/physiology , Norepinephrine/physiology , Rats , Stroke Volume/drug effects , Stroke Volume/physiologySubject(s)
Gastrointestinal Motility/physiology , Motor Activity/physiology , Activity Cycles , Animals , Animals, Newborn , Electrophysiology , Intestine, Small/growth & development , Intestine, Small/physiology , Isotonic Contraction/physiology , Muscle Development , Muscle, Skeletal/growth & development , Muscle, Skeletal/physiology , Rats , Rats, Wistar , Stomach/growth & development , Stomach/physiologySubject(s)
Aging/physiology , Motor Activity/physiology , Proprioception/physiology , Afferent Pathways/drug effects , Afferent Pathways/physiology , Aging/drug effects , Anesthetics, Local/administration & dosage , Anesthetics, Local/pharmacology , Animals , Injections, Intraperitoneal , Motor Activity/drug effects , Periodicity , Procaine/administration & dosage , Procaine/pharmacology , Proprioception/drug effects , Rats , Time FactorsABSTRACT
In experiments on newborn rats it was shown that heart beating frequency depended on the intensity of interoceptive afferentation. Partial shutdown of the afferentation by means of intraperitoneal injection of novocaine in the dose of 25 mg/kg of body weight caused the increase of heart beating and the more complete one at higher doses (100 mg/kg of body weight) led to its decrease. The injection of 2% novocaine (150-200 mg/kg of body weight) into the peritoneum of rat puppies on the first week of life caused the transition of bradycardia into temporary or permanent stop of heart beating. The same effect was observed for isolated atrium of rat puppies on the first week of life after the addition of 0.1% novocaine to feeding solution. This effect disappeared in older animals. It was concluded that resorptive effect of novocaine on heart structures causing the disturbance of heart automatism in newborn rats occurred along with the reflex one.
Subject(s)
Aging/drug effects , Anesthetics, Local/pharmacology , Heart Rate/drug effects , Procaine/pharmacology , Reflex/drug effects , Aging/physiology , Animals , Animals, Newborn , Atrial Function , Dose-Response Relationship, Drug , Electrocardiography/drug effects , Heart Atria/drug effects , Heart Rate/physiology , In Vitro Techniques , Rats , Rats, Wistar , Reflex/physiology , Statistics, NonparametricABSTRACT
The effect of intraperitoneally injected (25 mg/kg) novocaine (procaine) on the spontaneous periodic motor activity was investigated in rat puppies ageing from 1 to 14 days. It was shown that reactions were phasic: initial continuous and then elevated activity was followed by depression and recovery. The duration and intensity of stimulation and depression decrease with age. It was concluded that in newborn animals an excitability of motor centers depends on the level of interoceptive afferentation. The last may be one of the motor activity regulation mechanisms. The role of this mechanism decreases with age in favour of extero- and proprioception mechanisms of motor control.
Subject(s)
Motor Activity/physiology , Periodicity , Proprioception/physiology , Afferent Pathways/drug effects , Afferent Pathways/physiology , Aging/drug effects , Aging/physiology , Anesthetics, Local/pharmacology , Animals , Animals, Newborn , Electrocardiography/drug effects , Electromyography/drug effects , Motor Activity/drug effects , Procaine/pharmacology , Proprioception/drug effects , Rats , Rats, WistarSubject(s)
Heart Rate , Macaca mulatta/physiology , Macaca/physiology , Posture , Animals , Electrocardiography , Male , Wakefulness/physiologySubject(s)
Body Fluids/metabolism , Extracellular Space/metabolism , Plethysmography, Impedance/methods , Abdomen , Animals , Posture , Rats , ThoraxSubject(s)
Echocardiography , Heart/physiology , Macaca mulatta/physiology , Macaca/physiology , AnimalsABSTRACT
Water balance parameters were measured in hypokinetic rhesus monkeys using tritiated water. During exposure the water content decreased by 18.4%, with 11.3% lost within the first 7 days. The rate of water renovation measured with respect to H3 half-life was decreased by a factor of 1.5 during the first week and increased by 10% during the second week, as compared to the pretest value. Daily water losses diminished by 30% during the first week and approached the pretest level during the second week. These findings are indicative of three phases in the time-course variations of water balance during head-down tilt.