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Biomedical subjects

S F Lunn

Publications and source records attributed to S F Lunn.

At least 55 records · Page 3Linked to original sources
PubMed1982

Plasma progesterone levels throughout the ovarian cycle of the common marmoset (Callithrix jacchus).

Radioimmunoassay of progesterone in marmoset plasma has been used to determine ovarian cycle length. Total cycle length was 30.1 +/- 3.8 days (mean +/- SD, n = 30, range 24-41 days, median 29.5 days). The pre-ovulatory (follicular) phase, during which progesterone levels were below 10 ng/ml, lasted for 8.8 +/- 3.7 days (mean +/- SD, n = 30, range 3-20 days, median 8.5 days). The post-ovulatory (luteal) phase, during which progesterone levels were greater than 10 ng/ml, lasted for 21.5 +/- 2.2 days (mean +/- SD, n = 30, range 14-29 days, median 21.5 days). Total cycle length was almost twice that recorded in an earlier study. The reasons for this difference are discussed.

Animals↗
PubMed1981

Plasma prolactin concentrations during the ovarian cycle and lactation and their relationship to return of fertility post partum in the common marmoset (Callithrix jacchus).

A heterologous double-antibody radioimmunoassay was used to measure plasma prolactin concentrations in 27 marmosets. The assay was valid for the marmoset because plasma levels of prolactin were increased in response to TRH and metoclopramide and suppressed in response to bromocriptine treatment. During the cycle there were no consistent changes in plasma prolactin concentrations. During lactation mothers suckling single or twin infants had higher prolactin levels than did non-suckling females and levels were highest with twins. No statistically significant delay in the resumption of ovulation post partum was observed for the suckling and non-suckling females; conception occurred in all but one marmoset by 70 days post partum. These results show that neither the suckling stimulus nor high levels of prolactin post partum delay the return of ovulation and fertility in the common marmoset, a result in contrast to that for all other primate species so far investigated.

Animals↗
PubMed1981

Inhibition of ovarian function in subordinate female marmoset monkeys (Callithrix jacchus jacchus).

Plasma concentrations of progesterone, cortisol, LH and prolactin were measured in dominant and subordinate female marmosets in 10 well-established peer groups. Subordinate females never ovulated, had a reduced LH response to LH-RH and showed no positive feedback LH surge after oestrogen administration. There was no evidence of elevated plasma cortisol levels or hyperprolactinaemia in subordinates and all showed a similar prolactin response to TRH in comparison with dominants. However, subordinates showed a reduced prolactin response to metoclopramide. These results clearly indicate that high circulating levels of cortisol or prolactin are not responsible for the inhibition of ovulation in female marmosets.

Animals↗
PubMed1979

Pregnancy diagnosis in the common marmoset (Callithrix jacchus jacchus).

Abdominal palpation of the uterus was carried out on 25 pregnant and 29 non-pregnant marmosets (Callithrix jacchus jacchus). 195 complete 24-hour urine specimens, collected between the first week of gestation and term (21 weeks), were tested with the Sub-Human Primate Tube (SHPT) test. No significant differences between the two methods in their ability to diagnose pregnancy were obtained between the first and 13th week of gestation. The SHPT test was seldom positive after the 13th week of pregnancy, whereas, with one exception, palpation always indicated pregnancy.

Animals↗
PubMed1978

Use of the common marmoset, Callithrix jacchus, in reproductive research.

A self-sustaining colony of common marmosets, Callithrix jacchus, was established for reproductive research. Methods of management were developed to ensure optimal breeding conditions for marmosets in captivity. Studies of the reproductive biology and endocrinology of this species suggest that the common marmoset may be a suitable model for the human in certain aspects of the ovarian cycle, pregnancy, puberty and the hypothalamic and pituitary control of luteinizing hormone secretion. The rapid rate of reproduction of C. jacchus in captivity allows a relatively large colony to be maintained at moderate cost and also makes this species a most suitable laboratory primate for longer term studies of the safety and efficacy of new contraceptive methods.

Aging↗
PubMed1977

Urinary excretion of biologically active chorionic gonadotrophin by the pregnant marmoset (Callithrix jacchus jacchus).

No significant correlation exists between the amount of biologically active marmoset chorionic gonadotrophin (mCG) in urine and results obtained with an immunological pregnancy test. The pregnant marmoset excretes large amounts of oestrogenic steroids, which must be removed, to prevent the enhancement of the response of the bioassay for mCG. More than 99% of these unconjugated and conjugated urinary oestrogens can be removed by extraction with acetone and ether. mCG is excreted throughout pregnancy, maximum levels occurring between the 8th and 9th week of gestation. There is a considerable within- and between-animal variation in the amount of mCG excreted. However, the pattern of gonadotrophin excretion by the pregnant marmoset is similar to that of man and the apes but unlike that of baboons and macaques.

Animals↗
PubMed1975

Management of marmosets for biomedical research.

The management of a successful breeding colony of common marmosets, Callithrix jacchus, is described, including details of treatment during the conditioning period after arrival from the wild. Methods are described for the collection of blood, urine, and vaginal washings. Suggestions are made for improving the conditions of importation of these animals from South America.

Animals↗