title: Influence of acute intracerebroventricular (i.c.v.) administration of adrenocorticotrophin (ACTH) on LH secretion in male rats: effect of pretreatment (i.c.v.) with ACTH antiserum on the serum LH response to an acute ether stress.
abstract: Adult male rats with chronic indwelling intracerebroventricular (i.c.v.) and jugular catheters were given an i.c.v. injection (over 1 min) of 1, 10, 100 ng or 1 microgram ACTH(1-24), or 300 ng ACTH(4-10) or saline, and blood samples were taken 0, 5, 15, 30 and 60 min later. Increasing dosages of ACTH(1-24) caused a dose-related rise in serum LH levels. Peak levels of serum LH (ranging from 157 to 473% of pretreatment levels) were reached 5-15 min after treatment, and then serum LH values returned to pretreatment levels by 60 min. The serum LH response to 1 microgram ACTH(1-24) did not differ from the response to 100 ng ACTH(1-24). Administration (i.c.v.) of 300 ng ACTH(4-10) was also effective in increasing serum LH values. Repeated withdrawal of blood during the experiment increased serum corticosterone values in all groups (including saline-treated), but i.c.v. administration of ACTH(1-24) or ACTH(4-10) did not further increase serum corticosterone levels. Two additional groups of rats were injected i.p. with either saline or pentobarbital (30 mg/kg body weight) 1 h before i.c.v. administration of 10 ng ACTH(1-24) and blood samples were taken as in the other groups. The animals in these groups did not show a rise in serum LH concentrations in response to ACTH(1-24). In a third experiment, rats were pretreated (i.c.v.) with either ACTH antiserum (ACTH-Ab) or normal rabbit serum 15 min before a 2-min ether stress. The ether stress evoked a significant rise in serum LH concentrations within 15 min.(ABSTRACT TRUNCATED AT 250 WORDS)
mesh_terms: D000324:Adrenocorticotropic Hormone / Q000008:administration & dosage / Q000276:immunology / Q000494:pharmacology*; D000818:Animals; D000906:Antibodies / Q000276:immunology*; D002552:Cerebral Ventricles; D004305:Dose-Response Relationship, Drug; D004986:Ether / Q000494:pharmacology*; D005019:Ethyl Ethers / Q000494:pharmacology*; D007276:Injections, Intraventricular; D007986:Luteinizing Hormone / Q000097:blood*; D008297:Male; D051381:Rats; D011919:Rats, Inbred Strains
chemical_list: D000906:Antibodies; D005019:Ethyl Ethers; D004986:Ether; D000324:Adrenocorticotropic Hormone; D007986:Luteinizing Hormone