Age-dependent Changes in the Responsiveness of Hypothalamic Pituitary Gonadal Axis in Men

Age-dependent Changes in the Responsiveness of Hypothalamic Pituitary Gonadal Axis to Kisspeptin-10 Administration in Men

The present study was designed to assess the responsiveness of the hypothalamic pituitary gonadal axis to kisspeptin administration with increasing age in men.

Little is known about the involvement of kisspeptin signalling in the causation of senescence-basal modulation of the GnRH-LH unit in any model and particularly in advance age men. The present study was therefore designed to assess the response of hypothalamic pituitary gonadal axis to kisspeptin administration with increasing age in healthy men. Sequential blood samples (2 ml) were obtained for 30 minutes pre and 120 minutes post-kisspeptin injection periods at 30 min intervals (-30, 0, 30, 60, 90, 120). Kisspeptin-10 was administered (1 µg/kg BW) as an intravenous bolus, immediately after collecting 0 min sample to assess the response of GnRH neurons to kisspeptin-10 with increasing age in men by determining plasma levels of LH and testosterone.

Healthy men, 15 in number were selected. These individuals were classified on the basis of their ages in three groups: adult, middle age and advanced aged. Each group comprised of five participants.

There was no masking. Every individual was told about injecting the kisspeptin, however, they were not informed at the time when kisspeptin was injected.

The average age was 25.80±0.37 years and intervention human kisspeptin-10 was administered in single iv bolus dose (1 µg/kg BW). Serial blood samples were collected for 30 min pre and 120 min post-kisspeptin injection periods at 30 min interval.

The average age was 47.00±0.77 years and intervention human kisspeptin-10 was administered in single iv bolus dose (1 µg/kg BW). Serial blood samples were collected for 30 min pre and 120 min post-kisspeptin injection periods at 30 min interval.

The average age was 73.20±0.91 years and intervention human kisspeptin-10 was administered in single iv bolus dose (1 µg/kg BW). Serial blood samples were collected for 30 min pre and 120 min post-kisspeptin injection periods at 30 min interval.

Kisspeptin-10 (metastin 45-54, Calbiochem, Darmstadt, Germany) is a potent HPG-axis stimulator and control reproduction.

To investigate the basal function of KISS1R on GnRH neurons through serum LH and testosterone during aging in men

Two blood samples at 30 minutes interval before kisspeptin injection were obtained from all the groups to determine basal levels for LH and testosterone.

Changes in the sensitivity of KISS1R by determining the responsiveness of GnRH neuron to kisspeptin administration after 30 minutes during aging in men through measuring plasma luteinizing hormone and testosterone concentrations

One blood sample from all individuals were obtained after 30 minutes of post kisspeptin injection for measuring a change in LH and testosterone.

Changes in the sensitivity of KISS1R by determining the responsiveness of GnRH neuron to kisspeptin administration after 60 minutes during aging in men through measuring plasma luteinizing hormone and testosterone concentrations

One blood sample from all individuals were obtained after 60 minutes of post kisspeptin injection for measuring a change in LH and testosterone.

Changes in the sensitivity of KISS1R by determining the responsiveness of GnRH neuron to kisspeptin administration after 90 minutes during aging in men through measuring plasma luteinizing hormone and testosterone concentrations

One blood sample from all individuals were obtained after 90 minutes of post kisspeptin injection for measuring a change in LH and testosterone.

Changes in the sensitivity of KISS1R by determining the responsiveness of GnRH neuron to kisspeptin administration after 120 minutes during aging in men through measuring plasma luteinizing hormone and testosterone concentrations

One blood sample from all individuals were obtained after 120 minutes of post kisspeptin injection for measuring a change in LH and testosterone.

Inclusion Criteria: • Age Exclusion Criteria: Hepatic and renal complications Epilepsy Pneumonia Asthma Orchitis Hernia Cryptorchidism Cardiovascular diseases Reproductive disorders Mental retardation

After publishing will be available to all researchers. Additional data will be provided by the corresponding author on request.

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