17-Hydroxylase: an evaluation of the present view of its catalytic role in steroidogenesis.

This survey analyses the evidence that has led to the belief that the catalytic role of 17-hydroxylase in the biosynthesis of cortisol, estradiol, testosterone and dehydroepiandrosterone is confined to two chemical reactions: pregnenolone-->17-hydroxypregnenolone-->dehydroepiandrosterone. This analysis suggests that the evidence supporting this view is not compelling enough to accept it unquestioningly. Different interpretations of the data can suggest other catalytic roles for 17-hydroxylase that are worthy of consideration. One such alternative is proposed.

Serum prolactin levels in homosexual and bisexual men with HIV infection.

OBJECTIVE: Prolactin is a neurohormone that may be secreted in response to stress and also has regulatory effects on the immune system. Some, but not all, studies suggest that prolactin levels are higher than normal in persons with HIV infection. The authors measured prolactin levels in HIV-positive and HIV-negative homosexual and bisexual men to assess possible differences in levels and then examined relationships between prolactin level and measures of medical status, anxiety, depression, stress, and neuropsychological test performance. METHOD: Blood for prolactin level determination was obtained from 121 HIV-seropositive and 79 HIV-seronegative homosexual and bisexual men enrolled in a longitudinal study. The men also underwent a daylong assessment that included medical, immunological, psychiatric, psychosocial, psychosexual, and neuropsychological evaluations. RESULTS: There was no statistically significant difference in serum prolactin level among the seronegative men, the seropositive men with no or minimal physical symptoms, and the seropositive men with significant physical symptoms of HIV infection. Furthermore, within the HIV-seropositive group, the correlations between serum prolactin level and measures of depression, anxiety, stress, and neuropsychological test performance were all nonsignificant. CONCLUSIONS: Serum prolactin level does not seem to respond to HIV infection or to be related to stress or psychiatric symptoms in HIV-infected men. As none of the subjects had AIDS, the possibility cannot be ruled out that prolactin level increases in very late stages of HIV infection.

Measurement of plasma homovanillic acid concentrations in schizophrenic patients.

1. Several lines of evidence suggest that abnormalities of central dopaminergic transmission may be involved in the expression of some schizophrenic symptoms. However, elucidation of the role of dopamine (DA) in schizophrenia has eluded investigative efforts partially because no accurate and easily repeatable measure of brain DA activity exists. 2. The development of a technique to measure homovanillic acid in plasma has offered the possibility of performing serial measurements of this major DA metabolite. 3. Assuming that plasma homovanillic acid (PHVA) concentrations is an index of brain DA activity, measurement of PHVA can play a role in elucidating the DA abnormality in schizophrenia. 4. Results to date suggest that plasma homovanillic acid concentrations are lower in chronic schizophrenic patients compared to normal controls, and that PHVA values correlate with schizophrenic symptom severity. 5. In addition, PHVA levels were shown to initially rise and subsequently decline during chronic neuroleptic administration in treatment responsive but not in treatment refractory schizophrenic patients.

Modulation of the kinetics of cholesterol side-chain cleavage by an activator and by an inhibitor isolated from the cytosol of the cortex of bovine adrenals.

Two modulators of sterol side-chain cleavage activity have been detected in the cytosol from the cortex of bovine adrenals. One is an inhibitor of side-chain cleavage which increases the Km of a purified and reconstituted mitochondrial side-chain cleavage system for both cholesterol and cholesterol sulfate. It also lowers the Vmax of cleavage when cholesterol sulfate is the substrate. The other modulator is a low molecular weight protein which in the reconstituted system increases the Vmax of cleavage for both substrates but does not affect the Km of either. Side-chain cleavage activity was also found in bovine adrenocortical cytosol and this appears to differ from that present in mitochondria.

Solid-phase reagents for the isolation and protection of carbonyl compounds.

Resins which can serve as solid-phase Girard reagents have been prepared. These consist of porous cross-linked polystyrene-divinylbenzene matrices functionalized either with acid hydrazide groups, 1 or with O-alkylhydroxylamine groups, 2. Both resins react rapidly, under acid catalysis, with steroidal ketones and with glucose to form resin bound carbonyl derivatives. The carbonyl compound can be recovered by exchange with acetone under mildly acidic conditions. Resin 2 was used to extract steroidal ketones from an extract of bovine adrenals. By protecting the C-20 ketone group of allopregnanolone, resin 2 was used to prepare the counterpart of the steroid bearing tritium in the 3 alpha-position.