ABSTRACT
In situ hybridization procedure with a 32P-labelled synthetic oligonucleotide probe was used to detect corticotropin-releasing factor-encoding messenger RNA (CRF mRNA) in the hypothalamus of the white sucker, Catostomus commersoni. Adjacent sections were immunostained by a sucker CRF-specific antiserum. CRF mRNA-containing neurons were identified by autoradiography in the magnocellular and parvocellular subdivisions of the preoptic nucleus (PON). Many of these neurons were also immunostained by sucker antiserum, showing the same distribution patterns. These results confirm the presence of CRF mRNA and CRF peptide in the white sucker hypothalamus and support the view that the magnocellular and parvocellular neurons of the PON may be involved in the control of adrenocorticotropic hormone secretion from the pituitary in the white sucker.
Subject(s)
Corticotropin-Releasing Hormone/genetics , Fishes/genetics , Hypothalamus/chemistry , RNA, Messenger/analysis , RNA, Messenger/genetics , Animals , Autoradiography , Base Sequence , Female , Immune Sera , Immunohistochemistry , Male , Molecular Sequence Data , Neurons/chemistry , Nucleic Acid Hybridization , Oligonucleotide Probes , Phosphorus Radioisotopes , Preoptic Area/chemistryABSTRACT
The relaxant action of vasoactive intestinal peptide (VIP) was investigated using helical strips of four major branches of bovine coronary arteries. The concentration of VIP causing 50 percent of maximal relaxation ranged from 23 to 90 nM. Preincubation of arterial strips with VIP shifted the concentration-response curves for contractions elicited by potassium chloride or prostaglandin F2 alpha to the right. The relaxant effect of VIP was retained following removal of the vascular endothelium or in the absence of extracellular calcium. The structurally homologous peptides porcine and human peptide histidine isoleucine (PHI) were less potent than was VIP. It is concluded that there are functional receptors for VIP in bovine coronary arteries.
Subject(s)
Muscle, Smooth, Vascular/drug effects , Vasoactive Intestinal Peptide/pharmacology , Animals , Calcium/physiology , Cattle , Coronary Vessels/drug effects , Dinoprost/pharmacology , Endothelium, Vascular/drug effects , In Vitro Techniques , Muscle Relaxation/drug effects , Peptide PHI/pharmacology , Potassium Chloride/pharmacologySubject(s)
Muscle Contraction/drug effects , Muscle Relaxation/drug effects , Muscle, Smooth, Vascular/drug effects , Peptides/pharmacology , Prostaglandins/pharmacology , Urotensins/pharmacology , Animals , Arachidonic Acid , Arachidonic Acids/pharmacology , Arteries/drug effects , Aspirin/pharmacology , Atropine/pharmacology , Dose-Response Relationship, Drug , Indomethacin/pharmacology , Male , Norepinephrine/pharmacology , Propranolol/pharmacology , Pyrilamine/pharmacology , Rats , Rats, Inbred StrainsABSTRACT
Using a high specificity radioimmunoassay, antidiuretic hormone (ADH) concentrations were measured in the plasma of 33 expectant mothers during labour, in cord arterial and venous plasma of their infants at the time of delivery (19 delivered vaginally; 14 delivered by Cesarean section) and in the plasma of the same infants in the first few days of life. Extremely high concentrations of ADH (about 50 times higher than adult basal concentrations) were present in cord arterial blood indicating active fetal production of ADH. Plasma ADH decreased rapidly within an hour after birth and usually fell to adult basal levels during the first day of life. Stressed babies and babies subjected to difficult deliveries had higher plasma levels of ADH.
