Serum prolactin levels and prolactin binding activity in adrenals and kidneys of male rats after dehydration, salt loading, and unilateral nephrectomy

Serum prolactin (PRL) levels and PRL binding activity in microsomal membranes from kidneys and adrenals were measured in control, water-deprived, unilaterally nephrectomized, and salt-loaded male rats. Unilateral nephrectomy and water deprivation increased serum prolactin levels significantly. Unilateral nephrectomy did not alter PRL binding activity in the kidneys, but significantly increased it in the adrenal glands. Salt loading had no effect on serum prolactin levels or PRL binding in the kidneys; but significantly increased PRL binding in the adrenal glands. Inhibition curves and tests of cross reactivity with LH, FSH, TSH, and GH showed that binding of PRL to its receptors in the kidneys and adrenals was specific. These observations suggest that PRL has a role in salt and water metabolism and that PRL receptors in the kidney and adrenals participate in this regulatory system.

Intermittent catheterization rather than urinary diversion in children with meningomyelocele

Fifteen girls more than 4 years old and with neuromuscular defects of meningomyelocele are maintaining adequate urinary continence through the use of intraurethral catheterization done by themselves or their parents. Urinary diversion has been necessary in only 1 child. The indwelling catheter has allowed heavily trabeculated bladders to become smooth enough for an antirflux operation to be successful, although the period of followup is only 2 years. Upper tract deterioration has not been observed and urine has been maintained sterile without the help of medication 50 per cent of the time when catheterizations have been done on a routine 3-hour schedule. For this method to be sucessful and replace conduit deversion, parents, child, nurse and physician must be a well-knit team. With the hope that a reliable artificial urinary sphincter will eventually provide contience for some children, one is further justified in pursuing urinary continence by use of the catheter, instead of resorting early to permanent conduit conversion.

Prolactin binding activity on the crop sacs of juvenile, mature, parent and prolactin-injected pigeons

Specific prolactin (PRL) binding activity of lactoperoxidase catalyzed 125I-labeled ovine-PRL was determined in a membrane-rich particulate fraction of pigeon crop sacs. Levels of TSH, LH or FSH as high as 1000 ng each were unable to displace the 125I-o-PRL bound to 600 mug of crop sac microsomal protein, whereas competitive displacement was achieved with as little as 0.5 ng unlabeled PRL. Ovine GH exhibited some cross reactivity when incubated in amounts greater than 500 ng, but this could be accounted for by its stated PRL contamination. Specific PRL binding activities were determined in juvenile and mature pigeons with unstimulated crop sacs, and parent pigeons with 'crop milk' and mature birds injected with PRL for 4 days. Crop sacs from juvenile birds contained approximately twice as much binding activity as crop sacs from mature pigeons. Parent and PRL injected pigeons, each with proliferated crop sac epithelium, exhibited 4-5 times as much specific PRL binding as the non-proliferated crops from juvenile or mature birds. These results show that the pigeon crop sac contains specific binding sites for PRL, and that the crop sac response to PRL is associated with an increase in PRL binding activity.

New rifampin-resistant mutant of Escherichia coli

A rifampin-resistant ribonucleic acid (RNA) polymerase mutant, rif(r)51, derived from a presumptive RNA synthesis mutant of Escherichia coli K-12, complements rif(r) RNA polymerase mutants isolated from other strains of E. coli K-12.