The Puerto Rican parrot reintroduction program: sustainable management of the aviary population.

The cornerstone of the recovery plan for the critically endangered Puerto Rican parrot (Amazona vitatta) is an actively managed, long-term reintroduction program. One captive population distributed across two aviaries in Puerto Rico is the sole source for release but its ability to persist as a managed resource has not been evaluated since 1989. We conducted an assessment for sustainable management of the aviary population while harvesting for release.

Renal tumors in male rats following long-term administration of bazedoxifene, a tissue-selective estrogen receptor modulator.

Bazedoxifene acetate (BZA) is a selective estrogen receptor modulator that is approved in a number of countries for the prevention and/or treatment of osteoporosis in postmenopausal women. To assess carcinogenic potential, BZA was administered ad libitum in the diet to male and female rats for 2 years. The achieved mean dosages of BZA were approximately 1.

Carcinogenicity and hormone studies with the tissue-selective estrogen receptor modulator bazadoxifene.

Bazedoxifene Acetate (BZA) is a selective estrogen receptor modulator (SERM) that is approved for the prevention and/or treatment of osteoporosis in postmenopausal women. To assess for carcinogenic potential, BZA was administered ad libitum in the diet to rats for 2 years. BZA caused an increase in benign ovarian tumors in female rats and decreased incidences of mammary tumors (females) and pituitary tumors (males and females).

Extinction risk assessment for the species survival plan (SSP) population of the Bali mynah (Leucopsar rothschildi).

The Bali mynah Species Survival Plan (SSP), an Association of Zoos and Aquariums program, strives to maintain the genetic and demographic health of its population, avoid unplanned changes in size, and minimize the risk of population extinction. The SSP population meets current demographic and genetic objectives with a population size of 209 birds at 61 institutions and 96% genetic diversity (GD) retained from the source population. However, participating institutions have expressed concerns regarding space allocation, target population size (TPS), breeding restrictions, inbreeding depression, and harvest in relation to future population availability and viability.

Cathepsin B mRNA and protein expression following contusion spinal cord injury in rats.

We provide the first data that cathepsin B (Cath B), a lysosomal cysteine protease, is up-regulated following contusion-spinal cord injury (SCI). Following T12 laminectomy and moderate contusion, Cath B mRNA and protein expression profiles were examined from 2 to 168 h post-injury in rats using real-time PCR and immunoblots, respectively. Contusion injury significantly increased [mRNA]Cath B in the injury site and adjacent segments over sham injury levels.

Induction of manganese superoxide dismutase in acute spinal cord injury.

Free radical-mediated mechanisms of cellular damage have been implicated in the early stages of spinal cord injury (SCI). Manganese superoxide dismutase (MnSOD) is a potent scavenger of superoxide radicals and likely serves an important cytoprotective role in preventing cellular damage after SCI. We have evaluated the expression of MnSOD to address its role during the early events of SCI using a well-established rat contusion model.

Proton transfer to residues of basic pK(a) during catalysis by carbonic anhydrase.

The maximal velocity in the hydration of CO(2) catalyzed by the carbonic anhydrases in well-buffered solutions is limited by an intramolecular proton transfer from zinc-bound water to acceptor groups of the enzyme and hence to buffer in solution. Stopped-flow spectrophotometry was used to accumulate evidence that this maximal velocity is affected by residues of basic pK(a), near 8 to above 9, in catalysis of the hydration of CO(2) by carbonic anhydrases III, IV, V, and VII. A mutant of carbonic anhydrase II containing the replacement His-64-->Ala, which removes the prominent histidine proton shuttle (with pK(a) near 7), allows better observation of these basic groups.

Introduction of histidine analogs leads to enhanced proton transfer in carbonic anhydrase V.

The rate-limiting step in the catalysis of the hydration of CO2 by carbonic anhydrase involves transfer of protons between zinc-bound water and solution. This proton transfer can be enhanced by proton shuttle residues within the active-site cavity of the enzyme. We have used chemical modulation to provide novel internal proton transfer groups that enhance catalysis by murine carbonic anhydrase V (mCA V).

The catalytic properties of murine carbonic anhydrase VII.

Carbonic anhydrase VII (CA VII) appears to be the most highly conserved of the active mammalian carbonic anhydrases. We have characterized the catalytic activity and inhibition properties of a recombinant murine CA VII. CA VII has steady-state constants similar to two of the most active isozymes of carbonic anhydrase, CA II and IV; also, it is very strongly inhibited by the sulfonamides ethoxzolamide and acetazolamide, yielding the lowest Ki values measured by the exchange of 18O between CO2 and water for any of the mammalian isozymes of carbonic anhydrase.

Properties of intramolecular proton transfer in carbonic anhydrase III.

We investigated the efficiency of glutamic acid 64 and aspartic acid 64 as proton donors to the zinc-bound hydroxide in a series of site-specific mutants of human carbonic anhydrase III (HCA III). Rate constants for this intramolecular proton transfer, a step in the catalyzed dehydration of bicarbonate, were determined from the proton-transfer-dependent rates of release of H2 18O from the enzyme measured by mass spectrometry. The free energy plots representing these rate constants could be fit by the Marcus rate theory, resulting in an intrinsic barrier for the proton transfer of deltaG0++ = 2.

Intramolecular proton transfer from multiple sites in catalysis by murine carbonic anhydrase V.

The hydration of CO2 catalyzed by carbonic anhydrase requires proton transfer from the zinc-bound water at the active site to solution for each cycle of catalysis. In the most efficient of the mammalian carbonic anhydrases, isozyme II, this transfer is facilitated by a proton shuttle residue, His 64. Murine carbonic anhydrase V (mCA V) has a sterically constrained tyrosine at the analogous position; it is not an effective proton shuttle, yet catalysis by this isozyme still achieves a maximal turnover in CO2 hydration of 3 x 10(5) s-1 at pH > 9.

Glutamate and aspartate as proton shuttles in mutants of carbonic anhydrase.

Maximal turnover rates for the hydration of CO2 and the depletion of 18O from CO2 catalyzed by carbonic anhydrase III (CA III) and carbonic anhydrase V (CA V) are limited by proton transfer involving zinc-bound water or hydroxide in the active site. We have investigated the capacity of glutamic and aspartic acids at position 64 in human CA III and murine CA V to act as proton shuttles in this pathway. The distance from the Calpha of position 64 to the zinc is near 9.

Effects of dietary protein on food and water intake in spontaneously hypertensive rats.

We have been studying the development of hypertension in spontaneously hypertensive rats (SHR) fed a low protein diet. The effects of a low protein diet upon food and water intake were examined. Body weight gain, food and water intake were measured in three to twenty-three week-old SHR and Wistar Kyoto rats (WKY) fed diets containing 8%, 15% or 25% casein.

Noradrenergic transmission in the isolated portal vein of the spontaneously hypertensive rat.

The effect of electrical field stimulation (1, 2, 5, 10 Hz for a total of 480 pulses at 15-minute intervals) on the release of 3H-norepinephrine from the superfused portal vein of spontaneously hypertensive rats (SHR) or Wistar-Kyoto rats (WKY) of various ages was studied. The ages of the animals were (in weeks) 5-6 (prehypertensive), 8-10 (young hypertensives), 16-18 (older hypertensives), and 28 (mature hypertensives). There was no difference in the release of 3H-norepinephrine or developed tension of the portal vein to any frequency of field stimulation of SHR or WKY at 5-6 weeks of age.

[Inhibitory effect of noradrenaline on dopamine release from the hypothalamus of the rat].

1. The release of dopamine from the anterior hypothalamic/preoptic region of the anesthetized and artificially ventilated rats was investigated in vivo using a superfusion technique with a push-pull cannula. L-DOPA and pargyline were added to synthetic cerebrospinal fluid superfusing the area.

[Implication of anterior hypothalamic dopamine in the regulation of arterial pressure].

The anterior hypothalamus is essential for the normal carotid sinus baroreceptor reflex. The dopamine innervation to this region is a projection from the dopaminergic A 14 cell group of the rostral hypothalamus. The anterior hypothalamic/preoptic region (AH/PO) was unilaterally superfused with buffer containing L-DOPA (10(-4) M) and the superfusate analyzed for dopamine using liquid chromatography with electrochemical detection.

In vivo dopamine release from the anterior hypothalamus of the rat.

The release of dopamine from the anterior hypothalamic/preoptic region of the anesthetized rat was investigated in vivo using a superfusion technique with a push-pull cannula. Dopamine was measured electrochemically after separation by liquid chromatography. The spontaneous release of dopamine was very low but detectable in some experiments.

A cannabinoid with cardiovascular activity but no overt behavioral effects.

Abnormal-delta8-tetrahydrocannabinol (ABN-delta8-THC) failed to elicit central nervous system and cardiovascular effects in laboratory animals. Abnormal-cannabidiol (ABN-CBD) was also devoid of overt behavioral effects but produced marked hypotension with only slight bradycardia in anesthesized dogs.

A potent antinociceptive cannabinoid which lacks opiate substitution properties in monkeys.

(-)-9-Nor-9beta-hydroxy-hexahydrocannabinol[(-)-9-nor-9beta-OH-HHC] produced hypotension and bradycardia in anesthetized dogs, was a potent antinociceptive agent in the mouse tail-flick and p-phenylquinone abdominal-stretching tests, but did not reverse the effects of morphine withdrawal in dependent monkeys.

Vasoconstrictor actions of delta8- and delta9-tetrahydrocannabinol in the rat.

Cardiovascular effects of delta8- and delta9-tetrahydrocannabinol (THC) were studied after systemic intravenous administration and intra-arterial administration into a perfused vascular bed in the urethane-anesthetized rat. Intravenous administration of delta8- and delta9-THC produced dose-related transient increases in blood pressure followed by more prolonged hypotensive responses and bradycardia. Intra-arterial administration of delta8- and delta9-THC into the perfused hindquarters of the rat produced an increase in perfusion pressure indicative of vasoconstriction.

Tolerance to the cardiovascular effects of delta9-tetrahydrocannabinol in the rat.

1. Daily intraperitoneal injections of delta9-tetrahydrocannabinol (delta9-THC, 10 mg/kg) resulted in tolerance to the effects of the cannabinoid on body weight and body temperature within 1-2 weeks of treatment. 2.