Cytophotometric assessment of granulosa cell protein and nucleic acid levels during the estrous cycle in rats treated with T-2 toxin.

Female Sprague-Dawley rats (160-180g.) with normal estrous cyclicity established by vaginal smears, were injected intraperitoneally with 0.45 mg/kg (low dose) or 0.68 mg/kg (high dose) of T-2 toxin, a trichothecene with potent protein inhibitory abilities. Control animals were injected with only the 100% ethanol vehicle. All animals were decapitated at 8 hours post-exposure, and their ovaries removed and processed for paraffin sectioning. Coomassie, Feulgen, and azure B/DNase staining procedures were used to show granulosa cell protein levels, F-DNA stainability, and basophilia/RNA levels, respectively. Quantification of these parameters was accomplished using scanning-integrating microdensitometry. T-2 toxin treatment groups had granulosa cell protein levels significantly lower than those of the control animals. However, rats exposed to the lower dose of T-2 toxin generally showed a more marked suppression of protein levels than the high dose group, regardless of the stage of the estrous cycle. In addition, rats that received lower doses of T-2 toxin had impaired translation and template activity in response to injury, when compared with the rats in the high dose group. These results are attributed to the lesser degree of circulatory impairment in the low T-2 toxin dosage group, which allows a higher amount of T-2 toxin to interact with the cells.

Adrenocortical metabolism and plasma corticosterone in soman intoxicated rabbits.

The organophosphate neurotoxin soman produced impairments in adrenocortical RNA and protein metabolism. Fasciculate and reticular cell RNA and protein contents were suppressed with sublethal to acutely lethal dosages (20, 30 and 40 micrograms/kg, s.c.) during the acute excitatory phase of intoxication and at 6-8 h post injection. All three dosages produced ca 90% inactivation of plasma cholinesterase. A transient elevation of plasma corticosterone occurred with 20 micrograms/kg soman whereas there was a protracted increase with 30 micrograms/kg. Corticosterone was not significantly elevated with 40 micrograms/kg, but death occurred at 13 +/- 4 min. Thus, the magnitude and/or nature of soman-induced metabolic impairments does not appear to prevent adrenal activation.

Quantitative cytochemical analyses of ovarian luteal and interstitial cell RNA in relation to plasma progestins during pseudopregnancy in the rat.

Luteal and interstitial cell RNA contents and circulating progesterone (P) and 20 alpha-hydroxypregn-4-ene-3-one (20 alpha-OH P) levels were measured during pseudopregnancy in order to characterize relationships between ovarian 20 alpha-OH P secretion and luteal regression. Functional luteolysis, as manifested in depressed P levels, was not associated with concurrent elevations in 20 alpha-OH P. Rather, augmented 20 alpha-OH P levels were evidenced in periovulatory periods at the onset and termination of pseudopregnancy, subsequent to RNA accumulation in both luteal and interstitial compartments. It is postulated that 20 alpha-OH P, the putative inactive metabolite of P, is produced by both ovarian compartments in a cyclic manner and in response to gonadotrophin released in the preovulatory period.