Table 1.
Quantitative electron microscopy analysis of GnRH terminals and their surrounding environment in the pericapillary zone of the median eminence
| Group | % Basal lamina in contact with neuroendocrine terminals | % Extracellular space in the pericapillary zone | LDCV density per GnRH terminal area | GnRH immunogold particles per LDCV | Mitochondria area fraction |
|---|---|---|---|---|---|
| Young | |||||
| Vehicle | 8.51 ± 1.86 | 27.50 ± 2.50 | 7.49 ± 0.63 | 2.79 ± 0.19 | 3.01 ± 0.32 |
| E2 | 9.42 ± 1.29 | 24.92 ± 1.95 | 8.90 ± 0.85 | 3.10 ± 0.55 | 3.86 ± 0.38 |
| Middle-aged | |||||
| Vehicle | 8.30 ± 1.77 | 26.99 ± 1.45 | 8.74 ± 0.15 | 2.47 ± 0.21 | 4.55 ± 0.57 |
| E2 | 9.98 ± 4.16 | 29.63 ± 2.67 | 10.87 ± 0.72 | 3.25 ± 0.22 | 3.25 ± 0.50 |
| Old | |||||
| Vehicle | 12.27 ± 1.85 | 25.13 ± 0.82 | 12.36 ± 1.42 | 3.53 ± 0.43 | 3.29 ± 0.48 |
| E2 | 10.36 ± 1.76 | 27.10 ± 1.78 | 9.50 ± 0.74 | 2.58 ± 0.39 | 3.67 ± 0.55 |
The density of large dense-core vesicles (LDCV) in GnRH terminal increased with age (F = 5.36; P < 0.05; n = 5 rats in each group) with a significant increase in old compared with young rats (P < 0.01). Other quantitative measures showed no significant effects of age or hormone. E2, Estradiol.