scholarly journals A switch from continuous to episodic testicular testosterone release in response to pulsatile LH stimulation in juvenile rhesus monkeys (Macaca mulatta)

2004 ◽  
Vol 183 (1) ◽  
pp. 61-68 ◽  
Author(s):  
S Ramaswamy ◽  
C R Pohl ◽  
G R Marshall ◽  
T M Plant
Keyword(s):  
Rhesus Monkey ◽  
Macaca Mulatta ◽  
Cell Biology ◽  
Rhesus Monkeys ◽  
Leydig Cells ◽  
Testicular Function ◽  
Single Chain ◽  
Testosterone Secretion ◽  
Neuroendocrine Axis

This study examined the ontogeny of the testicular testosterone response to precocious pulsatile LH stimulation in the juvenile rhesus monkey. LH stimulation was achieved with an i.v. infusion (one pulse every 3 h) of either single-chain human (sch)LH, administered alone or in combination with recombinant human (rh)FSH, or recombinant monkey (rm)LH in combination with rmFSH. Homologous gonadotropin treatment resulted in an adult profile of circulating mLH concentrations. The schLH infusions produced a similar pulsatile pattern in circulating LH with peak concentrations of approximately 5 IU/l. Although a robust testicular testosterone response was observed after 24 h of intermittent LH stimulation, surprisingly testosterone release at this time was continuous. The apulsatile mode of testosterone secretion, however, did not persist, and a switch to an unequivocal episodic mode of secretion, comparable to that observed in adult monkeys, occurred by day 4 of LH stimulation. FSH did not influence the pattern of the testosterone response. We conclude from these findings that progenitor Leydig cells in the primate testis are able to respond rapidly to a physiological LH stimulus. While the cell biology underlying the switch from a continuous to a pulsatile mode of testosterone secretion remains unclear, we suggest that this phenomenon may be related to the hypothesis that episodic testosterone secretion is required for the operation of the neuroendocrine axis governing testicular function.

scholarly journals Selection for Urease Activity duringHelicobacter pylori Infection of Rhesus Macaques (Macaca mulatta)

2001 ◽  
Vol 69 (5) ◽  
pp. 3519-3522 ◽  
Author(s):  
Lori M. Hansen ◽  
Jay V. Solnick
Keyword(s):  
Helicobacter Pylori ◽  
Rhesus Monkey ◽  
Macaca Mulatta ◽  
Rhesus Monkeys ◽  
Urease Activity ◽  
Rhesus Macaques ◽  
Selection For ◽  
H Pylori ◽  
Selection Of

ABSTRACT Helicobacter pylori strain J166 recovered from experimentally inoculated rhesus monkeys had up to a 250-fold-increased urease activity over that before inoculation. This was found to result from the selection of urease positive J166 clones from a heterogenous inoculum, which was predominantly urease negative due to a 1-bp insertion in the ureA gene. These results confirm the importance of urease for H. pylori colonization. Strain J166 is particularly well adapted to the rhesus monkey, since it colonized preferentially despite the fact that less than 0.1% of the inoculum was urease positive.

THE NUMBER OF OOCYTES IN THE MATURE RHESUS MONKEY (MACACA MULATTA)

1951 ◽  
Vol 7 (2) ◽  
pp. 194-202 ◽  
Author(s):  
S. H. GREEN ◽  
S. ZUCKERMAN
Keyword(s):  
Statistical Analysis ◽  
Menstrual Cycle ◽  
Rhesus Monkey ◽  
Macaca Mulatta ◽  
Rhesus Monkeys ◽  
Significant Difference ◽  
Average Total Number ◽  
Sexually Mature

Estimates have been made of the total number of oocytes in ovaries removed on different days of the menstrual cycle from twelve sexually mature rhesus monkeys. They have been analysed on two assumptions: (a) that no relation exists over the range of age studied between age and the number of oocytes present; and (b) that such a relation exists. The data were grouped in the following three temporal phases of the menstrual cycle: days 1–9, days 10–18, days 19–27. Statistical analysis failed to reveal any significant difference between the average total number of oocytes present at the beginning, the middle, or the end of the menstrual cycle.

INFLUENCE OF OOPHORECTOMY, LUTEECTOMY, FOETAL DEATH AND DEXAMETHASONE ON THE PERIPHERAL PLASMA LEVELS OF OESTROGENS AND PROGESTERONE IN THE PREGNANT MACACA MULATTA

1974 ◽  
Vol 75 (3) ◽  
pp. 601-616 ◽  
Author(s):  
W. T. K. Bosu ◽  
E. D. B. Johansson ◽  
C. Gemzell
Keyword(s):  
Rhesus Monkey ◽  
Macaca Mulatta ◽  
Plasma Levels ◽  
Rhesus Monkeys ◽  
Deleterious Effect ◽  
Maternal Plasma ◽  
Relative Influence ◽  
Foetal Death ◽  
Bilateral Oophorectomy ◽  
Peripheral Plasma

ABSTRACT The influence of bilateral oophorectomy, luteectomy, dexamethasone injections and foetal death on the peripheral plasma levels of oestrogens1) and progesterone was studied in pregnant rhesus monkeys. After bilateral oophorectomy and luteectomy, pregnancy proceeded normally and the plasma levels of oestrogens and progesterone attained levels similar to those in intact monkeys, but the progesterone levels after parturition were comparatively lower. Dexamethasone injections into pregnant monkeys had no deleterious effect on the outcome of gestation. Abrupt and dramatic decreases in total oestrogens, oestrone and oestradiol levels occurred during dexamethasone injections into intact and oophorectomized pregnant monkeys but no significant changes in progesterone levels in plasma were observed. Spontaneous intra-uterine foetal death was accompanied by decrease in oestrogens, but no changes in the plasma levels of progesterone. In experimentally induced foetal death, the oestrogen and progesterone levels in plasma decreased prior to abortion. These data demonstrate the relative influence of the ovaries, adrenals and the placenta on the maternal plasma levels of oestrogens and progesterone in the pregnant rhesus monkey.

scholarly journals CANINE DISTEMPER IN THE RHESUS MONKEY (MACACA MULATTA)

1938 ◽  
Vol 67 (2) ◽  
pp. 323-332 ◽  
Author(s):  
Gilbert Dalldorf ◽  
Margaret Douglass ◽  
H. E. Robinson
Keyword(s):  
Rhesus Monkey ◽  
Macaca Mulatta ◽  
Rhesus Monkeys ◽  
Canine Distemper

Canine distemper has been transmitted to rhesus monkeys by a variety of methods. The disease is strikingly similar if not identical in its features with distemper in dogs.

Renal aplasia and hypoplasia in the rhesus monkey (Macaca mulatta)

1980 ◽  
Vol 14 (1) ◽  
pp. 1-2 ◽  
Author(s):  
Peter F. Wadsworth ◽  
Peter F. Squires
Keyword(s):  
Rhesus Monkey ◽  
Macaca Mulatta ◽  
Rhesus Monkeys ◽  
Compensatory Hypertrophy ◽  
Renal Aplasia

Unilateral renal aplasia or hypoplasia was discovered in 3 wild-caught rhesus monkeys at the end of routine toxicological experiments. No clinical abnormalities were evident and the opposite kidneys had undergone compensatory hypertrophy and hyperplasia.

GLYCOGEN METABOLISM IN FETAL, NEONATAL, AND INFANT MUSCLE OF THE RHESUS MONKEY

PEDIATRICS ◽  
1967 ◽  
Vol 40 (3) ◽  
pp. 412-420
Author(s):  
Rose Mary Bocek ◽  
Clarissa H. Beatty
Keyword(s):  
Rhesus Monkey ◽  
Macaca Mulatta ◽  
Rhesus Monkeys ◽  
Glycogen Metabolism ◽  
Aerobic Conditions ◽  
Hypoxic Conditions ◽  
Near Term ◽  
Glycogen Stores ◽  
Infant Rhesus ◽  
Glycogen Turnover

Muscle fiber groups from fetal, neonatal, and infant rhesus monkeys (Macaca mulatta) were incubated with glucose-C14 under aerobic and hypoxic conditions. Glycogen concentrations in the 90-day fetal and 4 to 5-day-old neonatal and infant series were lower when incubated under hypoxic than under aerobic conditions. The percent of glucose uptake appearing in glycogen was lowest at 90 days fetal age and highest in the infant series. Hypoxia markedly decreased glucose-C14 incorporation into glycogen. The dilution of the lactate-C14 produced indicated that glycogen turnover can be demonstrated under aerobic conditions as early as 90 days fetal age (55% of gestation) and that glycogen is mobilized from fetal and neonatal muscle under both aerobic and hypoxic conditions. Hypoxia increased glycogen mobilization, and the magnitude of glycogenolysis was similar in 90-and 120-day fetal, neonatal, and infant muscle but higher in muscle from fetuses near term (150 and 160 days). Therefore, the increased resistance of the near-term fetus to anoxia which would be fatal to older animals may be partially explained by the increased availability of glycogen stores.

THE COMPARATIVE POTENCY OF NATURAL AND SYNTHETIC OESTROGENS IN THE RHESUS MONKEY

1952 ◽  
Vol 8 (4) ◽  
pp. 291-307 ◽  
Author(s):  
P. ECKSTEIN ◽  
P. L. KROHN ◽  
S. ZUCKERMAN ◽  
M. J. R. HEALY
Keyword(s):  
Rhesus Monkey ◽  
Macaca Mulatta ◽  
Rhesus Monkeys ◽  
Intramuscular Injection ◽  
Uterine Bleeding ◽  
Threshold Dose ◽  
Threshold Levels ◽  
Single Intramuscular Injection ◽  
Oestradiol Benzoate ◽  
Latent Interval

1. The minimum amount of oestrogen, given as a single intramuscular injection, that is required to induce oestrogen withdrawal uterine bleeding ('threshold dose') has been estimated for eleven oestrogens in twenty-five spayed adolescent or mature rhesus monkeys (Macaca mulatta). 2. The threshold dose was always smaller when it was approached from supra-threshold dosage levels (falling series) than from sub-threshold levels (rising series). 3. The oestrogens tested can be arranged in the following decreasing order of potency: oestradiol dipropionate, stilboestrol dipropionate, oestradiol caprylate, oestradiol benzoate, oestradiol benz-butyrate, oestrone benzoate, stilboestrol, hexoestrol, oestradiol, oestrone, dienoestrol. 4. Esterification of the oestrogens increased the potency and duration of bleeding, but diminished the latent interval between the injection and the onset of bleeding. 5. Latency before bleeding was shorter, and duration of bleeding was longer the more potent the oestrogen. 6. The latent interval before bleeding was shorter for falling series of injections than for rising series of injections. 7. At doses above the threshold, latency before bleeding and duration of bleeding tended to become shorter.

Sign in / Sign up

Export Citation Format

Share Document