Plasticity of the mitochondrial genome in Podospora. Polymorphism for 15 optional sequences: group-I, group-II introns, intronic ORFs and an intergenic region.

The mitochondrial chromosome of 15 Podospora anserina and one Podospora comata wild-type strains have been extensively examined for the presence of optional elements and for sequence divergence. Among the P. anserina strains, nine optional sequences were found. By comparing P. anserina with the closely related and weakly interfertile P. comata species, six additional optional sequences were detected. These optional elements correspond to mitochondrial introns belonging to different groups and subgroups (11 cases), intronic open reading frames (two cases), a complex insert and an intergenic region. Although difficult to explain, the distribution of optional mitochondrial sequences among the 15 wild-type isolates of P. anserina is far from random.

Interaction between endogenous circulating sulfated-glycosaminoglycans and plasma proteins.

Interaction between endogenous 35S-labelled plasma glycosaminoglycans and proteins in murine plasma was demonstrated by coelution from gel chromatography of circulating 35S-labelled glycosaminoglycans with a wide range of plasma proteins. Autoradiography of electrophoretic tracing of proteins from 35S-sulfate labelled plasma showed that labelled glycosaminoglycans were associated with alpha 1, alpha 2, beta globulins and albumin, but not with gamma globulins. Analysis by gel chromatography on Sepharose CL-6B of delipidated 35S-labelled plasma after either proteolysis or beta-elimination, suggested that 35S-labelled glycosaminoglycan chains were covalently bound to proteins. Lipids were probably involved in the supramolecular assembly of GAGs with plasma proteins, as shown by hydrophobic interaction chromatography. In addition, strong, non-covalent interaction between glycosaminoglycan chains and proteins was responsible for the difficulty in extracting 'free' glycosaminoglycans from plasma. Consistently, ion-exchange chromatography of 35S-sulfate labelled delipidated plasma after alkali treatment, revealed that the anionic properties of glycosaminoglycans were hampered when plasma proteins were present.

Inhibition of superovulation and alteration of ova transportation in hamsters by prostaglandin and DL-204-IT, an anti-fertility agent.

The compound 2(3-ethoxyphenyl)-5, 6-dihydro-s-triazole- [5, 1-2] isoquinoline (DL-204-IT or L-11204) inhibited PMS-induced superovulation and reduced the number of recoverable ova in the oviducts of hamsters. PGE2 non-significantly reduced the number of ova shed but significantly decreased the number of oviductal ova. DL-204-IT was more potent than PGE2 for these effects. Administration of both compounds resulted in a complete block of ovulation. Inhibition of prostaglandin metabolism by DL-204-IT may be the cause for these effects, but no direct evidence is presently available.

A new non-hormonal pregnancy-terminating agent.

DL 111-IT, 3-(2-ethylphenyl)-5-(3-methoxyphenyl)-1H-1,2,4 triazole, a compound belonging to a new class of non-hormonal antifertility agents, when given subcutaneously, intramuscularly, intravaginally or orally terminates pregnancy in the rat, the mouse, the hamster and the dog. Time-course and dose-activity studies indicate that its effectiveness is dependent on dose, vehicle, route and time of pregnancy. DL 111-IT has no pre-implantation activity. The most effective time for treatment is the early post-implantation period. The compound has an antifertility effect through a slow and continuing action that results in the degeneration and subsequent resorption or expulsion of conceptuses. As a result, there must be sustained availability of active principle to arrest the pregnancy. Administered parenterally in a proper vehicle (oily) and with a suitable schedule of treatment (x 2-5 days), it demonstrates a very high pregnancy terminating activity (ED50: 0.04-0.7 mg/kg/day). Multiple intravaginal and oral administrations are also effective but the daily doses required are 10-20 and 40-100 times higher than the parenteral ones. Studies of the mechanism of action indicate that the site of action is the utero-placental complex. In fact, in pregnant rats, mice, hamsters and dogs, both plasma progesterone levels and the ineffectiveness of progesterone therapy rule out luteolysis as a basis for the activity. Moreover in hypophysectomized, ovariectomized animals whose pregnancies were maintained with proper hormonal treatments, DL 111-IT terminates pregnancy and adrenalectomy does not prevent its effect, which suggests that pituitary, ovaries and adrenals are not required for the antifertility action.

Effects of prostaglandin E2 and DL204 IT, an inhibitor of prostaglandin degradation, on ovulation and ovum transport in the hamster.

The effects of 2(3-ethoxyphenyl)-5,6-dihydro-s-triazole-[5,1-a]isoquinoline (L-11204 or DL 204 IT and PGE2 on ovulation and ova transport were studied. DI 204 IT was administered in doses of 0.2-25 mg/kg s.c. on the day of estrus. A smal reduction in ovulating follicles was observed 96 hours later, but only at the 5 mg/kg dose level. At all dose levels, however, DL 204 IT caused a dose-related reduction in the number of ova in the oviducts. PGE2 at a total dose of 2 mg/animal s.c., administered in 4 divided doses over the second and third day of the cycle did not affect ovulation or ova transport. PGE2 plus DL 204 IT (5 mg/kg), however, completely blocked ovulation in all but one animal. That animal had one ovulated follicle and a single ova was recovered from its oviduct.