A chronomorphological structural model of rat thyroid gland.
Circadian rhythmicity of the structural morphometric model of thyroid has been studied in 36 Wistar rats kept in LD 12:12. The parameters evaluated are: a. the volume fraction occupied by: 1. follicle epithelium, 2. colloid, 3. interstitium at 6 time points in 24h; b. the follicle size distribution; c. the number of follicles per unit tissue volume. The circadian rhythms of mean follicular diameter and of follicular cavity mean diameter have been demonstrated (p less than 0.03 and p less than 0.01 respectively) and show overlapping acrophases of -120 degrees (-64 degrees/-176 degrees) and -108 degrees (-99 degrees/-116 degrees). The synchronization between rhythms, shown for mean follicular diameter and for follicular cavity mean diameter, suggests a rhythmical pulsation of the whole follicle, while the thickness of the follicular epithelium does not undergo a statistically significant periodic variation.
Vizzotto
L
L
Istituto di Anatomia Umana Normale, Università degli Studi di Milano, Italy.
Sforza
C
C
Ferrario
V F
VF
Morini
M
M
Castellana
P
P
Bianchi
R
R
Dolci
C
C
Carandente
F
F
D000818:Animals; D002940:Circadian Rhythm; D004848:Epithelium / Q000033:anatomy & histology; D005260:Female; D008953:Models, Anatomic; D051381:Rats; D011919:Rats, Inbred Strains; D013961:Thyroid Gland / Q000033:anatomy & histology*