Ovulation in rhesus monkeys suppressed by intranasal administration of progesterone and norethisterone

Effects of intranasal administration of norethisterone on folliculogenesis, cervical mucus, vaginal cytology, endometrial morphology and reproductive-endocrine profile in women

The effects of intranasal administration of norethisterone (NET) on menstrual cycle length, folliculogenesis, serum levels of estradiol, FSH, LH and progesterone, vaginal cytology, cervical mucus and endometrial morphology were studied in 8 volunteers (age 28 to 39 years, weighing between 46 and 54 kg). The study period comprised 4 consecutive menstrual cycles. In the first cycle (pretreatment cycle), only the vehicle (alcohol, propylene glycol, water; 3:3:4) was sprayed intranasally (100 microliters in each nostril), using a metered nebulizer, once daily from day 3 to the last day of menstrual cycle. In the next two cycles (treatment cycles), NET (300 micrograms/day) was administered once daily, starting from day one of menstrual cycle, between 9 and 10 a.m. The fourth cycle was a post-treatment cycle in which the volunteers were monitored for recovery. Blood samples (about 5 ml each) were collected once daily from day 8 to 24 and thereafter on alternate days until the last day of cycle during all the 4 cycles. Levels of estradiol, FSH, LH and progesterone were measured in the serum samples by radioimmunoassay methods. Cervical mucus samples and vaginal smears were collected once daily starting from day 7 or 8 of each cycle until the mucus was very scanty. Serial pelvic ultrasonography was performed starting from day 7 or 8 until the growing follicle disappeared or throughout the cycle in case a growing follicular cyst was observed. Endometrial aspirates were collected once around day 22 in each cycle and processed for routine histological examination.

A simple, effective method of treating vertigo patients

Medical treatment of vertigo even today is far from satisfactory. A controlled clinical trial of treating vertigo patients by 1% ephedrine hydrochloride nasal douche has been conducted in 84 patients; 74.3% patients were either completely or partially relieved of their dizziness. The therapy was well accepted by patients and side effects were minimal.

beta-Endorphin: intranasal administration increases the serum prolactin level in monkey

Human beta-endorphin has been administered by nasal spray technique at a dose of 0.02 mg per kg in female bonnet monkeys. A significant increase of serum prolactin levels was observed within 30 min and maintained up to 60 min. In the same dose, intravenous injections of the hormone caused a marginal increase of prolactin levels only after 60 min. It was concluded that administration of beta-endorphin by nasal spray is more effective than the intravenous injection.

Reproductive endocrine effects of intranasal administration of norethisterone (NET) to women

Four consecutive menstrual cycles were studied in six healthy parous women. A solvent mixture comprising propylene glycol:ethanol:water (3:3:4) was sprayed intranasally daily using a glass atomizer between days 5 and 24 of the first (control) menstrual cycle. NET was dissolved in the solvent and similarly administered at a daily dose of 100 mcg during the second and third menstrual cycles. Nasal sprays were not administered during the fourth post-treatment cycle. Blood samples were taken during four consecutive cycles between days 8 and 15 and again between days 20 and 24 of the cycle to estimate levels of estradiol (E2), FSH, LH and progesterone (P). These studies revealed that nasal sprays of NET were well accepted and that no adverse clinical effects or menstrual disturbances occurred. NET inhibited ovulation in one cycle. The E2-induced mid-cycle rise in FSH and LH was either suppressed or inhibited in nine out of the 12 treated cycles. P levels in three treated cycles were indicative of luteal inadequacy. These endocrine effects of NET persisted into the post-treatment cycle in two cases.

Effect of intranasal administration of norethisterone and progesterone on pituitary and gonadal function in adult male and female bonnet monkeys (Macaca radiata)

The effect of intranasal spray of norethisterone (NET) and progesterone (P) on serum testosterone (T) and total sperm count in adult male bonnet monkeys and the effect of NET spray on the menstrual cycle in female monkeys has been studied. Whereas NET spray resulted in a drastic decrease in serum T levels and sperm count, P spray caused a decrease in total sperm count only. Intranasal spray of NET in adult cycling female monkeys between days 5 and 14 resulted in shortening of the menstrual cycle; this could be ascribed to a decrease in serum follicle-stimulating hormone, luteinizing hormone, 17 beta-estradiol, and P levels. Nasal spray of only solvent in male or female monkeys, however, had no effect on any of the parameters tested.

Pharmacokinetics of progesterone after its administration to ovariectomized rhesus monkeys by injection, infusion, or nasal spraying

The pharmacokinetics of progesterone (dose: 10 microgram per animal) were studied in blood and cerebrospinal fluid of adult ovariectomized rhesus monkeys after the administration of the steroid as an intravenous injection, intravenous infusion (duration of infusion: 10 min), or nasal spray. The bioavailability of progesterone, in terms of area under the time--concentration curve and the maximal concentration in the two body fluids, was significantly higher when the steroid was infused or sprayed intranasally than when it was injected intravenously. The clearance of the steroid from the serum, as estimated by its elimination rate constant, elimination half-life, and total body clearance, did not differ for the three methods of administration. These findings suggest that the bioavailability of progesterone is enhanced by extending the duration over which the steroid is delivered into the hemic circulation.

Bioavailability of progesterone enhanced by intranasal spraying

The bioavailability of progesterone (P) in terms of area under time-concentration curve and maximal concentration in the serum and cerebrospinal fluid was studied in adult ovariectomized rhesus monkeys following the administration of P as a nasal spray, i.v. or i.m. injections, nasal or eye drops. The bioavailability of P in both the body fluids was found to be considerably higher following its being sprayed intranasally.

17 beta-estradiol levels in blood and cerebrospinal fluid after ocular and nasal administration in women and female rhesus monkeys (Macaca mulatta)

17 beta-estradiol was applied ocularly to menstruating and postmenopausal women. The absorption by blood was measured. A rapid increase of both estradiol and estrone was seen with higher plasma levels in the menstruating group, possibly due to a better conjunctival circulation. Twenty-one rhesus monkeys were given estradiol suspension or solution ocularly or nasally. The absorption by blood and cerebrospinal fluid was measured and compared to intravenous injection of 0.5 mg estradiol. Estradiol increased in plasma after 1'. Maxima were reached at 15'. Estradiol solution gave higher plasma levels than estradiol suspension. At 5' they amounted to the levels found after i.v. injection. The estradiol levels in cerebrospinal fluid never exceeded the corresponding plasma levels and were generally low. The increase in cerebrospinal fluid was thought to be secondary to the raised plasma levels.

Treatment of rhesus monkeys (Macaca mulatta) with intravaginal rings impregnated with either progesterone or norethisterone

The effects of both progesterone- and norethisterone-loaded intravaginal rings were investigated in twenty-five rhesus monkeys for 52 weeks. The intravaginal rings were designed to provide a sustained release of either the human dosage level of the hormone or ten times this level. Untreated placebo rings were used for control purposes. The devices were well retained. With the exception of increased plasma fibrinogen levels in animals treated with norethisterone, no marked differences in either local or systemic toxicity between the progesterone and norethisterone intravaginal rings were apparent. Following insertion of the hormone-treated intravaginal rings, a dose-related decrease in vaginal bleeding was recorded. The vaginal microbial flora were assessed qualitatively and semiquantitatively and all groups including the placebo controls showed a changes in mcirobial populations. Terminal studies indicated that at high dose levels, ovulation was suppressed and widespread atrophy of the uterine mucosal and glandular endometrial epithelium had occurred. An increase in cervical mucus was observed within the lumen of the endocervical canal in a proportion of hormone-treated animals. In the vagina, a dose-related focal or diffuse atrophy of the mucosal epithelium was found.