남성화된 암컷 생쥐의 통각반응 양상과 에스트로겐-α 수용체의 발현 양상 = Pain Response Patterns and Expression of Estrogen-α Receptors in Androgenized Female Mice

국문 초록 (Abstract)

암컷 생쥐를 출생 직후 테스토스테론에 노출시키면 성장 후 통각반응과 중추신경계 통각조절부위의 estrogen-α 수용체(ERα)의 발현에 영향을 주는지를 조사하고자 하였다. 갓 태어난 생쥐(Institute for Cancer Research)에게 생후 24시간 이내에 testosterone propionate 100㎍(남성화군) 혹은 sesame oil 50㎕(대조군)씩 복강내 주사하였다. 13주째에 각 군을 반으로 나누고 naloxone HCI 5㎎/㎏ 혹은 동량의 생리식염수를 복강내 주사하였다. 15분 뒤에 Tail immersion test로 통각예민도(TFL, sec)를 2회 측정하였다. 이어서 모든 군에게 testosterone propionate 1㎎/㎏씩 복강내 주사하고, 15분 후에 같은 방법으로 TFL을 측정하였다. 8개월 째 식염수 전처치군의 뇌를 적출하여 일차감각대뇌겉질, 시상, 중간뇌수도관주위회색질, 큰솔기핵 및 허리와 엉치척수분절 부위를 분리하였다. 각 부위별 ERα를 Western blot 분석으로 반정량하였다. 그 결과는 다음과 같다.
생리식염수 전처치군에서 대조-암컷은 기저 TFL과 테스토스테론 투여 후 TFL이 대조-수컷 보다 유의하게 예민하였다. 테스토스테론은 모든 군에서 TFL을 유의하게 연장시켰다. 날록손 전처치-대조-암컷은 수컷이나 남성화-암컷 보다 유의하게 예민하였다. 남성화-암컷은 기저 TFL이 수컷 보다 예민한 경향이 있었고, 날록손이 테스토스테론의 진통효과를 감소시키는 경향이 있었다. 그 외는 수컷과 유사한 반응을 보였다.
남성화-암컷은 대조-암컷 보다 사상의 ERα western band의 광 밀도가 낮은 경향이 있었다. 그 외 부위는 세 군간 차이가 없었다. 대조-암컷은 수컷이나 남성화-암컷에 비하여 다른 부위 보다 시상에 밀집되어 있고, 큰솔기핵에는 적었다. 남성화-암컷은 수컷에 비해 중간뇌수도관주위회색질의 밀도가 다른 부위에 비해 낮은 경향이 있었지만, 다른 부위는 차이가 없었다.
이상의 결과로부터 출생직후 암컷 생쥐를 테스토스테론에 노출시키면 통각에 대한 반응이나 중추신경계 통각조절 부위의 ERα 발현 양상이 수컷과 비슷해진다는 결론을 얻었다.

다국어 초록 (Multilingual Abstract)

Objectives : The object of this study was to investigate the effects of neonatal exposure to testosterone in female mice on the pain responses and the expression of estrogen-α receptors(ERα) in the pain control areas of the CNS in their later life.
Methods : Testosterone propionate 100㎍ or sesame oil 50㎕ was injected intraperitoneally to neonatal mice within 24 hours after birth. In the 13th week of age, animals of each group(Androgenized-Female : AF ; Control-Female : CF ; Control-Male: CM) were divided into two and pretreated with naloxone HCI 5㎎/㎏ or saline 15 minutes before tail immersion test. Tall flick latencies(TFLs) were measured before and 15 min after administration of testosterone propionate 1㎎/㎏ i p.(intra-peritoneal) In the 8th month, mice were sacrificed and brains were dissected into primary sensory cortex, thalamus, periaqueductal gray, nucleus raphe magnus and lumbosacral spinal cord. ER α protein was assayed by Western blot analysis.
Results : In saline-pretreated groups, TFLs of CF measured before and after testosterone injection were significantly shorter than those of CM. Testosterone prolonged TFLs signficantly in all subgroups. Among naloxone-pretreated groups, CF was significantly more sensitive than CM and AF. TFL profiles of AF did not differ from that of CM, except that baseline TFLs were slightly shorter and naloxone seemed to decrease analgesic effect of testosterone in AF, though statistically not significant. 66kDa Western bands were detected in all 5 regions. Optic density(OD) of each area did not differ across 3 groups, except that OD of ER α In the thalamus in AF was lower than in CF. Percent OD of a region to sum of the 5 areas(OD%) showed significant difference in the thalamus and nucleus raphe magnus. CF showed higher OD% in the thalamus than in CM and AF, and lower OD% in nucleus raphe magnus than in CM and AF. Western bands profile of AF did not differ from that of CM.
Conclusion : These findings suggested that the pain response patterns and the expression of ER α in the pain control areas of CNS are grossly similar between androgenized female and control male mice.

목차 (Table of Contents)

• 영어 초록
• 서론
• 재료 및 방법
• 결과
• 고찰
• 요약
• 참고문헌

참고문헌 (Reference)

• 1 "찬물 강제수영이 남성화된 암컷 생쥐의 통각예민도에 미치는 영향" 7 (7): 66-67, 2001
• 2 "암 생쥐에서 naloxone이 testosterone으로 인한 유해감각예민도 둔화에 미치는 영향:남성화군과 대조군의 비교" 부산대학교병원 학술지 11 : 97-106, 2002
• 3 "남성화된 암컷 생쥐에서 testosterone이 통각예민도에 미치는 영향" 8 : 65-71, 2000
• 4 "expression within human forebrain Distinct distribution pattern to ERα mRNA" 3840-3846, jclinendocrinolmetab2000
• 5 "The mouse brain in stereotaxic coordinates" Academic Press paxi (paxi): 1988
• 6 "The maternal spinal cord:biochemical and physiological correlates of steroid-activated antinociceptive processes" 133 : 83-97, 2001
• 7 "Thalamic neuronal activity in rats with mechanical allodynia following contusive spinal cord injury" 117 : 715-722, 2003
• 8 "Synaptology of trigemino- and spinothalamic lamina I terminations in the posterior ventral medial nucleus of the macaque" 459 : 334-354, 2003
• 9 "Sex-related hormonal influences on pain and analgesic responses" 24 : 485-501, 2000
• 10 "Sex-dependent effects of restraint on nociception and pituitary-adrenal hormones in the rat" 55 (55): 789-793, 1994
• 11 "Sex related differences in the effect of morphine and stress on visceral pain" 28 : 967-970, 1989
• 12 "Sex differences in the perception of noxious experimental stimuli:a meta-analysis" 74 : 181-187, 1988
• 13 "Sex differences in the antagonism of swim stress-induced analgesia:effects of gonadectomy and estrogen replacement" 53 (53): 17-25, 1993
• 14 "Sex differences in androgen and estrogen receptor expression in rat substantia nigra during development:an immunohistochemical study" 115 (115): 685-696, 2002
• 15 "Sex and genotype determine the selective activation of neurochemically-distinct mechanisms of swim stress-induced analgesia" 56 (56): 61-66, 1997
• 16 "Reversal of sex difference in morphine analgesia elicited from the ventrolateral periaqueductal gray in rats by neonatal hormone" 929 : 1-9, 2002
• 17 "Production and actions of estrogens" 346 (346): 340-352, 2003
• 18 "Ovarian steroids and modulation of morphine-induced analgesia and catalepsy in female rats" 96 (96): 291-294, 1983
• 19 "Nociceptin(Orphanin FQ)abolishes gestational and ovarian sex steroid-induced antinociception and induces hyperalgesia" 750 : 48-52, 1997
• 20 "Neonatal testosterone exposure influences neurochemistry of non-opioid swim stress-induced analgesia in adult mice" 63 : 321-326, 1995
• 21 "Kappa-opioids produce significantly greater analgesia in women than in men" 2 : 1248-1250, 1996
• 22 "Immunolocalization of estrogen receptor β in the mouse brain:Comparison with estrogen receptor α" 144 (144): 2055-2067, 2003
• 23 "Gender-specific and gonadectomy-specific effects upon swim analgesia:role of steroid replacement therapy" 44 (44): 257-265, 1988
• 24 "Gender differences in two forms of cold-water swim analgesia" 37 : 893-897, 1986
• 25 "Estrogen-receptor-dependent regulation of nuclear stem cell proliferation and differentiation" 21 : 512-520, 2002
• 26 "Estrogen receptor-α distribution in the human hypothalamus in relation to sex and endocrine status" 454 : 115-139, 2002
• 27 "Estrogen receptor-alpha and beta-immunoreactivity and mRNA in neurons of sensory and autonomic ganglia and spinal cord" 304 : 193-214, 2001
• 28 "Estrogen effects on the brain:multiple sites and molecular mechanisms" 91 : 2785-2801, 2001
• 29 "Estrogen effects in the central nervous system" 20 (20): 279-307, 1999
• 30 "Estrogen actions throughout the brain" 57 : 357-384, 2002
• 31 "Estradiol inhibits ATP-induced intracellular calcium concentration increase in dorsal root ganglia neurons" 118 : 941-948, 2003
• 32 "Estradiol inhibits ATP-induced intracellular calcium concentration increase in dorsal root ganglia neurons" 118 : 941-948, 2003
• 33 "Endorphin-mediated increases in pain threshold during pregnancy" 210 : 193-195, 1980
• 34 "Dorsolateral funuculus and intraspinal pathways mediated vaginal stimulation-induced suppression of nociceptive responding in rats" 294 : 59-65, 1984
• 35 "Distribution of estrogen target sites in the 2-day-old mouse forebrain and pituitary gland during the 'critical period' of sexual differentiation" 16 (16): 11-22, 1991
• 36 "Differential roles of hypogastric and pelvic nerves in the analgesic and mortoric effects of vaginocervical stimulation in rats" 559 : 337-343, 1991
• 37 "Differential expression of estrogen receptor alpha and beta in rat dorsal root ganglion neurons" 57 : 603-615, 1999
• 38 "Developmental regulation of sex differences in the brain:Can the role of gonadal steroids be redefined" 60 : 843-855, 1994
• 39 "Comparative distribution of estrogen receptor-α and -β mRNA in the rat central nervous system" 388 : 507-525, 1997
• 40 "Brain-mediated responses to vaginocervical stimulation in spinal cord-transected rats:role of the vagus nerve" 708 : 128-134, 1996
• 41 "Brain formation of oestrogen in the mouse:sex dimorphism in aromatase development" 49 : 407-415, 1994
• 42 "Behavioral effects of estrogen gene disruption in male mice" 94 : 1476-1481, 1997
• 43 "Androgen influence sexual differentiation of embryonic mouse hypothalamic aromatase neurons in vitro" 135 (135): 1220-1226, 1994
• 44 "Analgesic effect of vaginal stimulation in rats:modulation by graded stimulus intensity and hormones" 16 : 483-438, 1976
• 45 "An increase in tryptophan in brain may be a general mechanism for the effect of stress on sensitivity to pain" 24 (24): 1019-1025, 1985