EFFECT OF TESTOSTERONE ON NEURONAL REFRACTORY PERIODS, SEXUAL BEHAVIOUR AND LUTEINIZING HORMONE: A COMPARISON OF TIME-COURSES

1981 ◽  
Vol 89 (1) ◽  
pp. 147-155 ◽  
Author(s):  
K. M. KENDRICK ◽  
R. F. DREWETT ◽  
C. A. WILSON
Keyword(s):  
Luteinizing Hormone ◽  
Sexual Behaviour ◽  
Plasma Levels ◽  
Refractory Period ◽  
Testosterone Propionate ◽  
Stria Terminalis ◽  
Refractory Periods ◽  
Sexual Responses ◽  
Time Courses

Measurements of the refractory period of stria terminalis neurones that are sensitive to testosterone propionate, of sexual behaviour and of plasma levels of LH were taken in castrated rats at various times after initiation of treatment with testosterone propionate. Levels of LH dropped within 24 h, before there was any change in neuronal refractory periods. The period of latency to mounting, however, was reduced to its shortest only after 7–8 days and ejaculations first occurred at the same time; these sexual responses correlated in time with the reduction of the neuronal refractory period to its lowest level.

EFFECTS OF 17β-HYDROXY-4-ANDROSTEN-19-OL-3-ONE (19-HYDROXYTESTOSTERONE) AND 5α-ANDROSTAN-17β-OL-3-ONE (DIHYDROTESTOSTERONE) ON ASPECTS OF SEXUAL BEHAVIOUR IN CASTRATED MALE RATS

1974 ◽  
Vol 61 (1) ◽  
pp. 105-115 ◽  
Author(s):  
R. F. PARROTT
Keyword(s):  
Adult Male ◽  
Sexual Behaviour ◽  
Testosterone Propionate ◽  
Male Rats ◽  
Organ Weights ◽  
Refractory Periods ◽  
Peripheral Effect ◽  
Rate Of Decline ◽  
The Brain ◽  
Experienced Adult

SUMMARY The ability of 19-hydroxytestosterone propionate (150 μg/day) to maintain sexual behaviour, accessory organ weights and the number of penile spines in experienced adult male rats in the 5 weeks after castration was compared with intact males and castrated animals receiving testosterone propionate (75 μg/day) or oil treatment. In a second experiment a group of male rats receiving dihydrotestosterone propionate (150 μg/day) was also included. 19-Hydroxytestosterone did not maintain ejaculatory performance but animals that ejaculated had refractory periods similar to those in intact and testosterone-treated groups. Dihydrotestosterone, however, slowed the rate of decline of ejaculatory performance but the refractory periods were comparable to those in castrated controls. The former action of dihydrotestosterone was attributed to its stimulatory effect on peripheral structures, especially the penile spines. 19-Hydroxytestosterone was shown to have no peripheral effect at doses up to 1800 μg every other day. The results are discussed in terms of a theory of testosterone action involving aromatization in the brain and 5α-reduction peripherally.

EFFECT OF PROSTAGLANDIN E2 ON MASCULINE SEXUAL BEHAVIOUR IN THE RAT

1977 ◽  
Vol 75 (3) ◽  
pp. 383-389 ◽  
Author(s):  
L. G. CLEMENS ◽  
B. A. GLADUE
Keyword(s):  
Prostaglandin E2 ◽  
Sexual Behaviour ◽  
Testosterone Propionate ◽  
Prostaglandin E ◽  
Intracerebral Infusion ◽  
Masculine Sexual Behaviour ◽  
Copulatory Behaviour

Intracerebral infusion of prostaglandin E2 (PGE2) facilitated copulatory behaviour of longterm castrated rats. Castrated rats were given daily systemic injections of testosterone propionate (50 pg) or oil vehicle, and then 30 min before behavioural testing they received an intrahypothalamic infusion of either PGE2 or saline. Rats receiving PGE2 in addition to systemic testosterone showed more copulatory behaviour than those receiving PGE2 or testosterone alone.

EFFECTS OF CONTINUOUS DAILY ADMINISTRATION OF 0.5 mg OF CHLORMADINONE ACETATE ON THE PLASMA LEVELS OF PROGESTERONE AND ON THE URINARY EXCRETION OF LUTEINIZING HORMONE AND TOTAL OESTROGENS

1970 ◽  
Vol 63 (4) ◽  
pp. 705-716 ◽  
Author(s):  
U. Larsson-Cohn ◽  
E. D. B. Johansson ◽  
L. Wide ◽  
C. Gemzell
Keyword(s):  
Luteinizing Hormone ◽  
Plasma Level ◽  
Urinary Excretion ◽  
Corpus Luteum ◽  
Plasma Levels ◽  
Chlormadinone Acetate ◽  
The Mean ◽  
Low Levels ◽  
The Difference ◽  
All Treatment

ABSTRACT Daily determinations of the plasma level of progesterone and the urinary excretion of luteinizing hormone (LH) and total oestrogens were performed in 6 subjects during one control cycle, immediately followed by three cycles of daily treatment with 0.5 mg of chlormadinone acetate continuously. The control cycles were ovulatory according to the parameters investigated. Two of the women showed a normal LH excretion pattern in all treatment cycles. The four other subjects also had periodical variations in the LH excretion but no distinct midcycle peaks occurred. The mean oestrogen excretion was increased in all three treatment cycles but the difference was satistically significant only in the last two cycles. Compared with the treatment cycles, the sum of progesterone values was significantly decreased in the first two cycles. Chlormadinone acetate in this dose had no thermogenic effect. Three of the subjects showed bleeding irregularities which had no clear connection with the hormone variations measured in the study. It is suggested that the low levels of progesterone might be due to a defective corpus luteum function.

Respiration-dependent Movements of the Column of Stylidium gvaminifolium

1981 ◽  
Vol 8 (1) ◽  
pp. 45 ◽  
Author(s):  
G.P Findlay ◽  
N Findlay
Keyword(s):  
Refractory Period ◽  
Angular Displacement ◽  
Metabolic Energy ◽  
Original Position ◽  
Firing Process ◽  
Mechanical Stimuli ◽  
Anaerobic Conditions ◽  
Absolute Refractory Period ◽  
Refractory Periods ◽  
Graded Responses

The column of the trigger plant, Stylidium graminifolium, when fully set responds to mechanical stimuli by flipping through an angle of about 4 radians in a fast firing movement lasting about 15-30 ms, and then slowly resetting to its original position in about 400 s. After resetting there is an absolute refractory period of about 500 s during which no further response to stimuli can be initiated, followed by a relative refractory period when graded responses increasing in rate and magnitude with time can be obtained. The resetting movement and the process, occurring during the refractory period, allowing subsequent firing to occur, are inhibited when the air surrounding the column is replaced by nitrogen. The firing movement, however, is not affected by these anaerobic conditions. Thus the firing movement is caused by passive physical forces, rapidly utilizing potential energy from a store built up during the previous resetting and refractory periods. Removal of the labellum, which the column touches when set, causes the column to oscillate with amplitude of about 3-3.5 radians and period of 1-2 ks. When the column is held at a constant angular displacement it develops an oscillatory torque with similar period. These oscillations are inhibited at all stages of the cycle by anaerobic conditions. It appears that the oscillatory behaviour is not a slowed-down firing process followed by normal resetting, but is linked throughout the cycle to the metabolic energy supply.

Sign in / Sign up

Export Citation Format

Share Document