PLASMA STEROID PROFILES IN MALE AND FEMALE MUDPUPPIES, NECTURUS-MACULOSUS (RAFINESQUE)

Plasma steroid profiles of healthy adult male and female mudpuppies, Necturus maculosus Rafinesque, were measured in animals sampled from November-June. Steroids in ether extracted plasma were analyzed directly by radioimmunoassay (RIA) for progesterone (P), total androgens, and total estrogens, or after Celite-ethylene glycol column chromatography for P, dihydrotestosterone (DHT), testosterone (T), estrone (E1), and estradiol-17β (E2). Steroid levels in both sexes were high compared to other vertebrates (10- to 100-fold greater), and highly variable at all times of the year. Comparison of the steroid profiles of males and females showed no qualitative differences; howeve, titers of all steroids (in ng/ml) were higher in males. Progesterone (P) ranged from 2.0-64.0, dihydrotestosterone (DHT) from 2.0-133, testosterone (T) from 4.0-202, estrone (E1) from N.D. to 1.87, and estradiol (E2) from 2.0-9.85 in adult males. In adult female Necturus, P ranged from N.D. to 15.5, DHT from 2.9-11.4, T from 1.5-8.3, and E2 from -0.4-6.35. E1 was not detectable. No clear seasonal variations in steroid titers or gonadal structure were observed although holding conditions at 5-8° did not approximate those in nature. © 1979.