Normal hemodynamic and coagulation responses to 1-deamino-8-D-arginine vasopressin in a case of lithium-induced nephrogenic diabetes insipidus. Results of treatment by a prostaglandin synthesis inhibitor (indomethacin).

The effect of 1-deamino-8-D-arginine vasopressin (DDAVP) on mean arterial pressure, pulse rate (PR), plasma renin activity (PRA), plasma factor VIIIc and von Willebrand factor were studied in a case of persistent lithium-induced nephrogenic diabetes insipidus (LINDI). 20% decrease in MAP, 22% increase in PR, 100% in PRA, and release of coagulation factors (2- to 3-fold) were noticed after infusion of 0.3 micrograms/kg DDAVP. Urinary prostaglandin (PG) E2 were enhanced. The treatment of this LINDI by PG synthesis inhibitor (PSI) combined with a low osmotic diet (LOD) led to a 51% fall in urine volume, 57% in free water clearance and 75% in sodium clearance. Urinary osmolality rose by 42% but remained low, probably in part because of the LOD. Urinary PGE2 was about one fifth of the initial high value. The results argue for (1) an end-organ resistance to DDAVP confined to the kidneys in LINDI and (2) an effectiveness of indomethacin combined with an LOD.     

Relaxant effect of rat PHI, PHI-Gly and PHV(1-42) in the rat gastric fundus.

It was previously shown that porcine PHI is 30 times less potent than VIP in relaxing the rat gastric fundus; the relaxant potency of rat PHI and its 2 C-terminally extended forms PHI-Gly and PHV(1-42) in the rat gastric fundus was compared here with that of VIP, porcine PHI and PHM. The rank order of potency in relaxing the precontracted fundus tissues was VIP greater than rat PHI greater than PHM greater than PHV greater than PHI-Gly greater than porcine PHI, rat PHI being only 2 times less potent than VIP. In the presence of antioxidants, the potency and efficacy of porcine PHI increased, but the peptide was still the least potent of the series tested. The results illustrate the importance of using species-related peptides and are compatible with a cotransmitter role of rat PHI in nonadrenergic noncholinergic neurotransmission of the rat gastric fundus.     

Androgen interactions with intact nuclear envelopes from the rat ventral prostate

Intact nuclear envelopes containing nuclear pore complexes have been prepared from the rat ventral prostate. The polypeptide profile of the nuclear envelopes from the rat prostate resembled that of nuclear envelopes prepared from the male rat liver. Isolation of the nuclear envelopes after incubation of purified nuclei with radioactive dihydrotestosterone results in labelling of the membrane. More dihydrotestosterone is bound after incubations at 22 degrees C for 18 h than at 2 degrees C for 18 h or 22 degrees C for 2 h. Scatchard analysis revealed a class of binding sites with an apparent Kd of 46 nM. Dihydrotestosterone, testosterone, cyproterone acetate and methyltrienolone were effective as competitors of labelled dihydrotestosterone binding to the nuclear envelopes, while estradiol did not compete. Castration of the rats 24, 48 and 96 h prior to preparation of nuclei resulted in loss of androgen binding to the membranes. Extraction with 0.6 M NaCl resulted in the loss of 72% of the androgen binding.     

Characterization of brevicin 27, a bacteriocin synthetized byLactobacillus brevis SB27

Lactobacillus brevis SB27, isolated from sausages, produced an antimicrobial substance active against numerous strains of heterofermentative lactobacilli and against some strains of pediococci andBacillus. The antibacterial agent was shown to be heat stable, resistant over a wide pH range, and sensitive to proteolytic enzymes. It was identified as a bacteriocin and termed brevicin 27. Dialysis and ultrafiltration suggested an apparent molecular weight between 10 and 30 kDa for the crude inhibitory molecule. Brevicin 27 exhibited a hydrophobic character. A partially purified preparation, resulting from ammonium sulfate precipitation and cation exchange chromatography, permitted confirmation of some characteristics of the bacteriocin, previously established with the crude extract. After treatment of the original brevicin 27-producing strain with novobiocin, a nonproducing mutant was obtained. This mutant was sensitive to brevicin 27, and its plasmid profile revealed the loss of a plasmid of about 3 MDa.     

The decline of atrial natriuretic peptide (ANP) gene expression in older rats and the effects of ginsenoside on ANP gene expression.

1. The levels of atrial natriuretic peptide(ANP) gene expression in rat atria at 2-3 and 14-18 months of age and the effects of ginsenosides on r-ANP gene expression by determining the concentration of ANP-mRNA were investigated. The male and female rats were abdominally (i.p.) injected with aqueous solution of ginsenosides prepared from ginseng stems and leaves (G-PSL) and ginseng roots (G-PR), 50 mg/kg body wt, once a day for 7 days. Atria total RNA was extracted by the cold phenol method. The ANP-mRNA contents were determined using the Northern blot and dot blot hybridization technique with alpha-32*P-labelled r-prepro-ANP-cDNA probe. 2. The ANP-mRNA contents of 14-18 month rats were remarkably less than that of 2-3 month rats. The levels of male and female rats' atria at 14-18 months were about 15 and 60%, the content of male and female rats at 2-3 months respectively. 3. G-PSL and G-PR increased the ANP-mRNA content of male rats at 14-18 months 1- and 2-fold, respectively, whereas G-PSL and G-PR decreased the ANP-mRNA content in male rats of age 2-3 months. 4. These results revealed that the ANP gene expression declined during ontogenic ageing development and ginsenosides possessed anti-ageing effects in the heart endocrineous function aspect.     

The organization of grooming in budgerigars

Structural rules for grooming are examined in the budgerigar (Melopsittacus undulatus). Two types of bouts are found: short bouts with no predictable temporal pattern and long bouts with some degree of periodic occurrence. Transitions in long bouts are mostly based on anatomical proximity. Grooming movements cluster together according to function and body region. Evidence for hierarchical organization obtained by clustering is confirmed by the proportion of occurrence of movements in long and short bouts. Individual birds are similar enough on measures of occurrence, transition and hierarchica structure for pooling of subjects to be justified; this suggests that the organizational rules found here are to a large extent species-typical.