Reproductive endocrinopathy in acute streptozotocin-induced diabetic male rats. Studies on LHRH.
Streptozotocin-(STZ) treated diabetic male rats have significant reproductive endocrinopathy. To determine the functional responsiveness of luteinizing hormone-releasing hormone (LHRH) neurons in STZ-treated diabetic male rats, stimulated LHRH release was assessed using hypothalami from short-term STZ-treated, STZ-treated insulin-replaced, and control male rats. LHRH release from control, STZ-treated, and STZ-treated, insulin-replaced explants in response to an initial and second 30-min pulse of phenylephrine were not different. A terminal pulse, containing 45 mM KCl, a general secretogogue, also revealed no differences between groups in stimulated LHRH release. Glucose and testosterone levels in the controls and the diabetic rats were significantly different. Cell counts on serial brain sections processed for LHRH immunohistochemistry suggested that the number of LHRH neurons in the preoptic area (POA) and septal areas were not different between control and STZ-treated rats. Thus, the short-term STZ-treated rats of this study were diabetic, and they displayed associated endocrinopathy; however, explants obtained from control and STZ-treated rats exhibited a typical LHRH responsiveness to both phenylephrine and KCl, and appeared similar in LHRH neuron number. Therefore, these findings suggest that reproductive endocrinopathy accompanying short-term STZ-induced diabetes in male rats does not result from deficiency in LHRH neurons per se.
Department of Anatomy, Southern Illinois University School of Medicine, Carbondale 62901-6503, USA. rclough@som.siu.edu
R W
RW
Clough
S G
SG
Kienast
R W
RW
Steger
D000316:Adrenergic alpha-Agonists / Q000494:pharmacology; D000818:Animals; D003921:Diabetes Mellitus, Experimental / Q000188:drug therapy / Q000503:physiopathology*; D007987:Gonadotropin-Releasing Hormone / Q000378:metabolism*; D007031:Hypothalamus / Q000378:metabolism*; D007328:Insulin / Q000627:therapeutic use; D008297:Male; D008473:Median Eminence / Q000378:metabolism; D009474:Neurons / Q000502:physiology*; D009919:Orchiectomy; D010656:Phenylephrine / Q000494:pharmacology; D011189:Potassium Chloride / Q000494:pharmacology; D051381:Rats; D017207:Rats, Sprague-Dawley; D013739:Testosterone / Q000494:pharmacology
D000316:Adrenergic alpha-Agonists; D007328:Insulin; D010656:Phenylephrine; D007987:Gonadotropin-Releasing Hormone; D013739:Testosterone; D011189:Potassium Chloride